United States Court of Appeals
                          FOR THE EIGHTH CIRCUIT
                                   ___________

                                Nos. 07-2057/2171
                                  ___________

Structural Polymer Group, Limited;    *
Structural Polymer Systems, Limited,  *
                                      *
      Appellees/Cross-Appellants,     *
                                      * Appeals from the United States
      v.                              * District Court for the
                                      * Eastern District of Missouri.
Zoltek Corporation,                   *
                                      *
      Appellant/Cross-Appellee.       *
                                 ___________

                             Submitted: January 14, 2008
                                Filed: October 8, 2008
                                 ___________

Before COLLOTON and SHEPHERD, Circuit Judges, and ERICKSON,1 District
Judge.
                         ___________

COLLOTON, Circuit Judge.

      A jury awarded Structural Polymer Group and Structural Polymer Systems
(together SP) $36,044,895 in lost profits from Zoltek Corporation for breach of a
requirements contract for the sale of carbon fiber. The district court2 reduced the

      1
       The Honorable Ralph R. Erickson, United States District Judge for the District
of North Dakota, sitting by designation.
      2
        The Honorable Carol E. Jackson, United States District Judge for the Eastern
District of Missouri.
award to $21,138,518, finding the remainder of the award duplicative. Zoltek appeals
the district court’s denial of its motion for a new trial and motion for judgment as a
matter of law. Structural Polymer cross-appeals the district court’s modification of
the jury’s damages award.3 We affirm.

                                           I.

       Zoltek is a Missouri corporation that manufactures and sells carbon fiber. SP
are British corporations that manufacture a strong, light-weight building material
produced using carbon fiber called “prepreg.” Prepreg is made by weaving carbon
fiber into textile-like sheets and then impregnating the sheets with liquid resin. The
prepreg sheets are then sold to builders who can mold them into different shapes for
a variety of applications. Used in this way, prepreg is a common substitute for
fiberglass. One common application for prepreg is the manufacture of wind energy
turbine blades.

       The parties entered into a Supply Agreement in November 2000. Under the
disputed agreement, Zoltek promised to manufacture and sell to SP all of SP’s
requirements between November 6, 2000, and December 31, 2010, for “Large
Filament Count Carbon Fibers (Carbon Fibers) as defined by PANEX 33
specifications,” at “then-current market price.” SP, in turn, promised to “obtain their
total requirements for suitable quality, in the reasonable opinion of [SP], Carbon
Fibers from [Zoltek],” the volume not to exceed “the amount actually purchased by
[SP] in the preceding Contract Year plus one million (1,000,000) pounds.” “Large
Filament Count,” or large-tow carbon fiber, contains 48,000 or more filaments per
bundle. “Small-tow” carbon fiber, by contrast, contains fewer than 48,000 filaments

      3
       SP also raised in its opening brief a challenge to the district court’s denial of
SP’s demand for specific performance of the contract, but SP later withdrew that
portion of the cross-appeal, after terminating the Supply Agreement effective February
29, 2008.

                                          -2-
per bundle, commonly 24,000 or fewer filaments per bundle. Small-tow is more
expensive to produce, but superior in quality.

      When the Supply Agreement was formed, most manufacturers used small-tow
carbon fiber. The purpose of the agreement was to develop a new market for large-
tow fiber as a less expensive alternative to small-tow fiber in the wind-energy
industry.

      Before April 2002, Zoltek produced a large-tow carbon fiber product called
Panex 33. SP purchased 28,219.17 and 20,943.91 pounds of Panex 33 from Zoltek
under the Supply Agreement in 2000 and 2001, respectively. SP placed an order for
1,763.70 pounds of Panex 33 in 2002, but returned it due to alleged quality defects.
In April 2002, Zoltek stopped manufacturing Panex 33, and started making a large-
tow carbon fiber product called Panex 35. SP ordered no Panex 33 or 35 in 2003. SP
ordered and received 548,935 pounds of Panex 35 in 2004.

      The dispute in this case centers on two orders that SP placed with Zoltek in
2005 and 2006 that were never filled. SP ordered 1,480,138 pounds of Panex 35 in
2005, and claims that it was entitled to 2,480,138 pounds of Panex 35 in 2006.

       On February 22, 2005, SP sued Zoltek for breach of contract alleging lost
profits through December 31, 2006, and future lost profits through December 31,
2010. Because the parties disputed whether the Supply Agreement entitled SP to both
Panex 33 and Panex 35, SP’s damages expert made alternative lost profit calculations:
$21,138,518 in then-current lost profits under Count I corresponding to 3,960,276
pounds of Panex 35, and $14,906,377 in then-current lost profits under Count II
corresponding to 3,000,000 pounds of Panex 33.

      On November 29, 2006, a jury awarded SP lost profits under both counts
through December 31, 2006, but declined to award SP future lost profits. The district

                                         -3-
court vacated the award under Count II as duplicative, giving SP a final sum of
$21,138,518. Zoltek filed motions under Federal Rule of Civil Procedure 59(a) for
a new trial, and under Rule 50(b) for judgment as a matter of law, in connection with
both the liability and damages phases of the proceedings, and the district court denied
both motions. Zoltek appeals the district court’s denial of those motions. SP cross-
appeals the district court’s vacation of the jury’s award under Count II of the
complaint.

                                           II.

       We review the district court’s denial of Zoltek’s motion for judgment as a
matter of law de novo to determine whether there is sufficient evidence to support the
verdict. Duty v. Norton Alcoa-Proppants, 

, 488 (8th Cir. 2002). In
reviewing the sufficiency of the evidence to support the jury’s verdict, we interpret the
record in a light most favorable to the prevailing party, affirming unless no reasonable
juror could have reached the same conclusion. Anderson Marketing, Inc. v. Maple
Chase Co., 

, 1065 (8th Cir. 2001). We review the denial of a motion
for a new trial for an abuse of discretion. The Shaw Group, Inc. v. Marcum, 

, 1067 (8th Cir. 2008). A new trial motion premised on a dispute about the
strength of the supporting proof should be granted only “if the verdict is against the
weight of the evidence and allowing it to stand would result in a miscarriage of
justice.” 

       Zoltek argues that the district court erred in four ways. First, Zoltek argues that
the district court erred by refusing to allow it to raise two arguments to the jury.
Zoltek sought to urge that the Supply Agreement was void for lack of mutuality of
obligation. The district court concluded that Zoltek’s argument was an affirmative
defense, which Zoltek waived by failing to plead it, and the district court then denied
as untimely Zoltek’s motion to amend its complaint to add a mutuality defense.
Second, the district court ruled that Zoltek failed to make a submissible case that SP

                                           -4-
had abandoned the Supply Agreement. Third, Zoltek argues that the district court
failed to remedy unfairly prejudicial testimony at trial. Fourth, Zoltek argues that the
jury’s damages award to SP was not based on adequate evidence, that the district court
erred by allowing SP to amend its damages calculations twenty-two days before trial,
that SP’s revised damages calculations were inadequate as a matter of law, and that
the district court instructed the jury incorrectly in connection with the damages phase
of the proceedings.

                                           A.

       We first consider Zoltek’s objection to the district court’s resolution of
arguments concerning mutuality of obligation. Zoltek urged that the Supply
Agreement was “unenforceable as a requirements contract due to a lack of mutuality,”
which is in essence an argument that SP failed to show that the Supply Agreement was
supported by valid consideration. See Restatement (Second) of Contracts § 79 (1981)
(“If the requirement of consideration is met, there is no additional requirement of . .
. ‘mutuality of obligation.’”); USA Chem, Inc. v. Lewis, 

, 24 (Mo. Ct.
App. 1977); Famous Brands, Inc. v. David Sherman Corp., 

, 521 (8th
Cir. 1987). We conclude that whether or not Zoltek’s contention should not have been
characterized as an affirmative defense, the district court correctly ruled in the
alternative that the Supply Agreement contained mutuality as a matter of law.

       SP contends that our decision in Overholt Crop Ins. Serv. Co. v. Travis, 

, 1368 (8th Cir. 1991), establishes that “lack of consideration” is an
affirmative defense that is waived if not raised in an answer. Overholt held that it was
unnecessary to reach the merits of an argument that certain restrictive covenants in a
contract were “void for lack of consideration,” because the defendants “waived this
affirmative defense by failing to raise it in their answer, see Fed. R. Civ. P. 8(c), and
by failing to identify any relevant exceptions to this general rule.” 

Zoltek
counters with our statement in First Union Nat’l Bank v. Pictet Overseas Trust Corp.,

                                          -5-


(8th Cir. 2007), that whether a contention “is an affirmative defense is
a question of [ ] state law,” 

and with Missouri authority that
distinguishes between “failure of consideration,” which is an affirmative defense
applicable where consideration that once existed becomes worthless or non-existent,
and “lack of consideration,” which is an element of the claim that cannot be waived
through failure to plead. Ennis v. McLaggan, 

, 561 (Mo. Ct. App.
1980); MFA Inc. v. Dettler, 

, 663 (Mo. Ct. App. 1991).

       Assuming for the sake of argument that Zoltek’s argument regarding lack of
consideration need not be pleaded as an affirmative defense, we agree with the district
court that the Supply Agreement was supported by adequate consideration as a matter
of law. Under Missouri law, “whether consideration is sufficient to establish a
contract is normally a question of law for the court and not a question of fact for the
jury.” Allison v. Agribank, FCB, 

, 188 (Mo. Ct. App. 1997). Missouri
law long has followed a rule that “[w]hen a party relies upon a writing or a number
of writings to establish a contract, it is unquestionably the province of the court to
determine from the writing or writings whether or not a contract was entered into.”
Nelson v. Cal Hirsch & Sons’ Iron & Rail Co., 

, 594 (Mo. Ct. App. 1903).

       Zoltek advances three reasons why the contract lacked mutuality of obligation.
All three are based on an allegation that SP’s requirements under the agreement are
“hopelessly manipulable” and determined by SP’s subjective preferences, rather than
by objective criteria outside of SP’s control. Specifically, Zoltek argues that “SP
could at all times order or not order Zoltek fiber as it wanted” because (1) SP had zero
requirements for large-tow fiber when the contract was formed, (2) the price
protection clause gave SP the option “to purchase carbon fibers from other producers”
whenever SP wanted to, and (3) SP was free to buy small-tow fiber, which Zoltek
alleges is “interchangeable” with large-tow fiber, in place of large-tow whenever it
pleased.



                                          -6-
       First, we disagree with Zoltek that the Supply Agreement lacks mutuality if SP
had zero requirements for large-tow fiber when the contract was formed. A duty of
good faith is implied in requirements contracts under Missouri law, see Mo. Rev. Stat.
§ 400.2-306(1) (1994); Home Shopping Club, Inc. v. Roberts Broad. Co., 

, 179 (Mo. Ct. App. 1998), and this “implied obligation of good faith is enough
to avoid finding a contract null and void due to an illusory promise.” Magruder
Quarry & Co., v. Briscoe, 

, 650-51 (Mo. Ct. App. 2002); see also
National Refining Co. v. Cox, 

, 781 (Mo. Ct. App. 1933). The Supply
Agreement bound SP to order product from Zoltek in good faith, and if SP failed to
purchase anything from Zoltek during the term of the agreement, then the contract
allowed Zoltek to allege that SP acted in bad faith by failing to make purchases. An
assertion of bad faith, however, is an argument that SP breached the agreement, not
that the agreement lacked mutuality or consideration in the first place. The district
court’s ruling on Zoltek’s proposed defense did not foreclose it from arguing to the
jury that SP breached the agreement.

       Second, we disagree with Zoltek that the price protection clause in the contract
made SP’s obligation illusory. The price protection clause gave Zoltek a right of first
refusal to sell large-tow carbon fiber to SP for the same price as offered by a third
party seller. If Zoltek offered to match the price offered by another supplier, then SP
was obligated to purchase from Zoltek. We think the Missouri courts are likely to
agree with the observation in a leading treatise that this mechanism does not render
the contract illusory:

      The seller may not promise to meet such prices, but the seller may be
      given the option of doing so. If the seller meets such prices, the buyer
      must buy of the seller or not at all. If the seller does not meet such
      prices, the buyer has the privilege of buying elsewhere. Such promises
      are not illusory and the contract is valid.

Arthur Linton Corbin, et al., 2-6 Corbin on Contracts § 6.8.


                                         -7-
        Zoltek’s authorities do not persuade us to the contrary. They demonstrate only
that if SP had an unfettered option to purchase from another supplier during the term
of the contract, then this option would destroy the exclusivity of the arrangement, and
demonstrate lack of consideration. E.g., In re Modern Dairy of Champaign, Inc., 

, 1108 (7th Cir. 1999); Harvey v. Fearless Farris Wholesale, Inc., 

, 459 (9th Cir. 1978); Loizeaux Builders Supply Co. v. Donald B. Ludwig Co., 

, 724 (N.J. Super. Ct. Law Div. 1976); Propane Indus., Inc. v. General
Motors Corp., 

, 221 (W.D. Mo. 1977). The inclusion in the Supply
Agreement of a right of first refusal for Zoltek to retain its exclusive right to supply
SP, so long as it matched a market price offered by another supplier, is sufficient to
create mutuality of obligation and consideration.

       Third, we do not agree with Zoltek that if small-tow and large-tow fiber are
“interchangeable,” then the Supply Agreement lacked mutuality. There was a good
deal of evidence at trial that small-tow and large-tow fiber are distinct products, with
different qualities and applications. But assuming for the sake of argument that a jury
could find that small-tow and large-tow fibers are in fact “interchangeable,” as Zoltek
contends, the authorities cited by Zoltek do not establish that the Supply Agreement
is void for lack of mutuality. These cases illustrate, rather, that when a buyer
contracts to purchase its requirements for a product from a particular seller, but then
– without a “good faith” basis to do so – purchases an interchangeable product from
a third party instead, the buyer may have breached the requirements contract. E.g.,
Fike Corp. v. Great Lakes Chemical Corp., 

, 524 (8th Cir. 2003); Empire
Gas Corp. v. American Bakeries Co., 

, 1339-41 (7th Cir. 1988);
Loudenback Fertilizer Co. v. Tenn. Phosphate Co., 

, 303 (6th Cir. 1903).
Zoltek was free to argue on this basis that SP’s purchase of small-tow fiber from
parties other than Zoltek was a breach of the agreement to purchase large-tow fiber
exclusively from Zoltek, but the jury found that SP performed its obligations under
the contract. SP’s obligation to purchase in good faith all of its requirements for



                                          -8-
large-tow fiber exclusively from Zoltek was sufficient consideration to make the
contract valid.

      For these reasons, we agree with the district court’s alternative holding that “on
the face of the agreement, there is mutuality of obligation and, therefore,
consideration.” Therefore, any error in characterizing lack of consideration as an
affirmative defense or in denying Zoltek’s motion to amend its complaint did not
prejudice Zoltek.

                                            B.

        Zoltek next contends that the district court erred by refusing to instruct the jury
on Zoltek’s theory that SP had abandoned the Supply Agreement. Zoltek asked the
court to give an instruction that the jury’s verdict must be for Zoltek if “the parties,
by their conduct, treated the 2000 Supply Agreement as if it were no longer in effect,
and thereby abandoned the 2000 Supply Agreement.” (Zoltek App. 425-26). The
district court refused the proposed instruction, and later stood by its decision in post-
trial orders. In denying Zoltek’s motion for judgment as a matter of law, the court
explained that Zoltek “argued in its trial brief that plaintiffs abandoned the
agreement,” that Zoltek argued “for the first time” in its post-trial motion that “the
parties mutually abandoned the 2000 Supply Agreement.” The court ruled that it
would “not address an argument raised for the first time in a post-trial motion.” (R.
Doc. 431, at 4).4

     Under Missouri law, whether abandonment is an issue for the court or the jury
depends on the nature of the argument advanced by the party claiming abandonment.

      4
       In its order denying Zoltek’s motion for a new trial, the district court
reaffirmed its ruling that Zoltek “had not made a submissible case that the parties
mutually abandoned the Supply Agreement,” (R. Doc. 430, at 13), presumably
because it believed that Zoltek had argued only that SP had abandoned the agreement.

                                           -9-
“When an abandonment by one party to a contract is predicated of certain specific
acts, or one given act, it is proper for the court to declare whether such act or acts
constitute an abandonment.” Chouteau v. Jupiter Iron Works, 

, 82 (1884)
(Chouteau I). Thus, it was error for the trial court in Henry v. Bassett, 

(1881), to submit to a jury the question whether a contract was abandoned or not, 

where “no mutual agreement of abandonment was alleged,” but it was “charged
that the plaintiff, Henry, had abandoned the contract” by taking certain specific acts.
Chouteau 

. In that circumstance, the trial court should have declared
whether the specified acts of the plaintiff were sufficient to constitute an
abandonment. 

.

       By contrast, “where a mutual agreement to abandon is relied upon, it may be
proved by an express agreement to that effect, or by circumstances which warrant the
inference, that the parties mutually agreed to abandon it.” Chouteau 

.
If certain acts by one party are insufficient by themselves to constitute abandonment,
then the jury should be so instructed, and the failure to do so is reversible error, 

but the question of mutual abandonment should be submitted to a jury, if the
evidence on the whole is sufficient to support a finding of abandonment. Chouteau
v. Jupiter Iron-Works, 

, 470 (Mo. 1887) (Chouteau II); see Bacon v. Boss,

, 210 (Mo. 1956) (citing Chouteau II). To be proved under Missouri
law, a mutual abandonment “must be demonstrated by positive and unequivocal acts
and conduct which are inconsistent with a mutual intention to be further bound by the
contract.” Waddington v. Wick, 

, 150 (Mo. Ct. App. 1983); see
O’Brien & Gere Technical Serv., Inc. v. Fru-Con/Fluor Daniel Joint Venture, 

, 455 (8th Cir. 2004) (Missouri law).

      In the district court, Zoltek argued that SP abandoned the Supply Agreement
when it purchased no carbon fiber from Zoltek between February 2002 and early
2004. We agree with the district court that the absence of orders by SP, even over a
period of more than two years, is insufficient to demonstrate a mutual abandonment

                                           -10-
of the Supply Agreement. A buyer under a requirements contract may, consistent with
the contract, reduce its requirements even to zero, as long as the buyer is acting in
good faith. See U.C.C. § 2-306 cmt. 2 (2004) (“Reasonable elasticity in the
requirements is expressly envisaged by this section and good faith variations from
prior requirements are permitted even when the variation may be such as to result in
discontinuance.”). That a buyer does so, therefore, is not a positive and unequivocal
act demonstrating abandonment, and the district court was correct to conclude that
SP’s acts did not constitute an abandonment. The jury, moreover, found that SP
performed its obligations under the Supply Agreement, thus rejecting any suggestion
that SP’s failure to order carbon fiber in 2003 and 2004 was a breach of the contract,
much less an abandonment.

       On appeal, Zoltek contends that a “Supply/Purchase Agreement” for Panex 35,
signed by the parties in April 2004, superseded the 2000 Supply Agreement and
demonstrated a mutual intent of the parties to abandon the 2000 contract. This
argument, however, was not presented in the district court, and we therefore decline
to consider it. Prior to the jury’s verdict, Zoltek never cited the 2004 contract as
evidence of mutual abandonment. Zoltek argued instead that the 2004 agreement for
Panex 35 showed that the 2000 Supply Agreement did not include Panex 35. (T. Tr.
2300-02). The district court, therefore, correctly observed that Zoltek advanced a
contention of mutual abandonment for the first time in its post-trial motions. The
court properly declined to instruct the jury on abandonment based on the arguments
then presented, and Zoltek’s subsequent reliance on the 2004 contract comes too late
to support a conclusion that the district court’s instructions were erroneous.

                                          C.

      Zoltek next contends that the district court admitted irrelevant and unfairly
prejudicial evidence at trial. We review the district court’s evidentiary decisions for
abuse of discretion. Hoselton v. Metz Baking Co., 

, 1059 (8th Cir. 1995).

                                         -11-
Zoltek focuses on SP’s use of a statement made by Zoltek’s attorney, Alan Kohn, at
a preliminary injunction hearing. In opposing SP’s motion for an injunction that
would have required Zoltek to provide SP with Panex 35, Kohn stated: “[T]hey have
no contract for Panex 35. All they have is some old Panex 33 contract which [Zoltek]
is ready, willing and able to perform.” (Zoltek App. 694). In later proceedings, SP
quoted Kohn’s statement, over Zoltek’s repeated objections, and argued that it was an
admission by Zoltek that the Supply Agreement entitled SP at least to a supply of
Panex 33. Zoltek contends that the Kohn statement was taken out of context and used
to mislead the jury.

       The district court allowed SP to quote the Kohn statement, but also gave Zoltek
an opportunity to present evidence to place the statement in what Zoltek argued was
the proper context. Zoltek’s CEO testified that the quotation from Kohn was a
“mischaracterization of what he said,” and that “[i]n balance,” what Kohn said was
“reasonable.” He testified that Kohn meant that “there was a failed or an old contract
which [Zoltek] would be ready, willing, and able to perform against if it [had not
been] breached by multiple breaches,” but that Kohn’s “unfortunate single statement
by itself [ ] is not representative of what should have [been] said.” (T. Tr. 1941)
(emphasis added).

       A statement by a party’s attorney can be admissible as an admission by a party
opponent if it is relevant. Harris v. Steelweld Equip. Co., 

, 403 (8th Cir.
1989). Given the context in which Kohn made his statement, the district court
concluded that Kohn’s statement was relevant as an admission that Zoltek was willing
to perform under the 2000 Supply Agreement by producing Panex 33 to SP:

      There was no misinterpretation. I understood exactly what he said to me
      at that hearing. . . . So you can characterize it any number of ways that
      you want to. But when I left that hearing, I thought that Panex 33 was
      going to be supplied to the plaintiffs but not 35, as they had asked for
      now, that was my impression; and I think it was a reasonable impression

                                         -12-
      and a reasonable conclusion to draw, based on what was said during that
      hearing.

(T. Tr. 59-60).

        The court’s conclusion that Kohn’s statement was relevant on this basis was not
an abuse of discretion. Although the specific issue presented in the preliminary
injunction hearing was whether Zoltek was required to provide Panex 35, Kohn relied
on Zoltek’s asserted willingness to provide Panex 33 in an effort to persuade the court
to deny the motion. Having made the statement in an effort to gain advantage in the
litigation, we do not think Zoltek can establish that the district court abused its
discretion by permitting SP to invoke counsel’s statement as a potential admission.
The district court adequately guarded against any unfair prejudice by permitting
Zoltek’s CEO to place Kohn’s statement in what Zoltek believed to be the proper
context, and to offer a mitigating explanation for Kohn’s comment.

       Kohn’s argument is different from the attorney statement that was held to be
irrelevant and inadmissible in Schneider v. Lockheed Aircraft Corp., 

,
843 (D.C. Cir. 1981). In that case, the purported “admission” was made in the context
of litigation involving a defendant’s third-party complaint for indemnity and
contribution. The disputed statement by counsel was prefaced with a caveat that the
allegations at issue were “assumed to be true” for purposes of a motion to dismiss the
third-party complaint. The court in Schneider held that third-party pleadings were
excepted from “the general rule of admissibility,” because “[t]he goals of efficient
federal procedure would be frustrated if hypothetical pleadings from third-party
proceedings could be introduced into evidence.” 

The court reasoned that
the “purely contingent statements” concerning the third-party complaint were
irrelevant to the issues in the underlying lawsuit. The statement by Zoltek’s counsel,
of course, was not made in the context of a third-party pleading, and it was not the sort
of hypothetical assumption involved in a defendant’s third-party complaint for


                                          -13-
contribution and indemnity. We therefore conclude that Schneider is distinguishable,
and that the district court’s ruling was not reversible error.5

                                           D.

                                           1.

      Zoltek argues that the jury’s damages award to SP was based on impermissible
speculation and other improper grounds. Zoltek contends that SP’s damages
calculations were based only on summaries of lost sales provided by SP management,
conversations with SP management, and projected sales from SP budgets, and that
none of these sources were sufficiently reliable to support the jury’s verdict.




      5
        Zoltek argues that the alleged error in admitting Kohn’s statement was
“compounded” by a statement of Paul Lyon, SP’s Group Purchasing Manager, that
“[t]here was a judgment from this court, I believe that said Zoltek had to supply Panex
33.” Zoltek says that Lyon mischaracterized the result of the preliminary injunction
hearing. The district court sustained Zoltek’s objection to Lyon’s testimony, and
instructed the jury to disregard the statement. Zoltek asked the district court also to
give a curative instruction “at the time the instructions are read to the jury that the
Court made no merits determination on either Panex 33 or Panex 35 at the time of the
injunction hearing.” Zoltek argues on appeal that “the District Court flatly refused to
give any curative instruction, and simply told the jury to disregard the statement.”

       The district court, however, did instruct the jury before deliberations that “[a]ny
testimony that I struck from the record or told you to disregard is not evidence and
must not be considered.” This instruction, together with the court’s action at the time
of the objection, was sufficient to cure any prejudice that might have been caused by
the testimony. Harrison v. Purdy Bros. Trucking Co., 

, 353 (8th Cir.
2002); Lockley v. Deere & Co., 

, 1389 (8th Cir. 1991). To the extent
Zoltek asserts that the district court erred by failing to give the jury a more specific
instruction before deliberations, we conclude that there was no abuse of discretion.

                                          -14-
       We apply state law to evaluate whether a jury’s damage award is adequately
supported by the record. Tipton v. Mill Creek Gravel, Inc., 

, 918 (8th
Cir. 2004) (Missouri law). Under Missouri law, “[l]ost profits related to a breach
preventing performance are recoverable provided the loss is the natural and proximate
result of the breach, is ascertainable with reasonable certainty, is not speculative or
conjectural, and was within the contemplation of the parties when the contract was
made.” Farmer’s Electric Co-op., Inc. v. Missouri Dep’t of Corrections, 

, 522 (Mo. 2001).

       Under Federal Rule of Evidence 703, “an expert may rely on otherwise
inadmissible hearsay in forming [her] opinion if the facts and data upon which [she]
relies are of a type reasonably relied upon by experts in the field.” Arkwright Mut.
Ins. Co. v. Gwinner Oil, Inc., 

, 1182 (8th Cir. 1997). The expert’s
opinion should be excluded only if it is “so fundamentally unsupported that it cannot
help the factfinder.” South Cent. Petroleum, Inc. v. Long Bros. Oil Co., 

, 1019 (8th Cir. 1992) (internal quotation omitted). As a rule, questions
regarding the factual underpinnings of the expert’s opinion affect the weight and
credibility of her testimony, not its admissibility. 

said that “[o]nce
expert testimony has been admitted, the rules of evidence then place the full burden
of exploration of facts and assumptions underlying the testimony of an expert witness
squarely on the shoulders of opposing counsel’s cross-examination.” Brennan v.
Reinhart Inst’l Foods, 

, 451 (8th Cir. 2000) (internal quotation omitted).

      We conclude that the jury’s award in this case was adequately supported by the
record. SP’s damages expert, Donna Smith, calculated SP’s lost profits based
primarily on a document created by SP’s then-Managing Director called “Summary
of Vestas and Gamesa Lost Sales,” budget figures kept in the ordinary course of
business by SP, conversations with SP management, deposition testimony of Zoltek
personnel, and Zoltek’s annual reports and investor presentations. Smith testified that
the method and sources she used to calculate SP’s lost profits was “generally accepted

                                         -15-
by experts in this field.” Zoltek had an opportunity to challenge Smith’s assertion that
her sources were consistent with professionally accepted standards, and to dispute the
reliability of the underlying factual information on which she relied. The sources
were not so slight as to be “fundamentally unsupported,” and the weight to be given
Smith’s opinion was properly left to the jury.

       The district court reasoned that Smith compared the sales projections provided
by SP’s Managing Director with actual purchases, and found that the amounts were
substantially equal. Relying in part on Zoltek’s own projection that demand for fiber
was expected to exceed supply for years to come, Smith testified that SP could have
processed and sold all of the Panex 35 to which it was entitled to under the Supply
Agreement. SP presented evidence that it could have sold 3,960,276 additional
pounds of Panex 35 between 2005 and 2006 due to a market-wide shortage of carbon
fiber. Zoltek’s CEO himself agreed that given the state of the market, Zoltek would
be able to sell whatever carbon fiber it was able to make for the foreseeable future.
(Zoltek App. at 1075-76).

       Smith’s report verified that SP possessed adequate manufacturing capacity to
process 3,960,276 additional pounds of Panex 35 between 2005 and 2006, and
subtracted variable costs not incurred as a result of Zoltek’s alleged breach. To arrive
at the $21,138,518 award, Smith multiplied the volume of Panex 35 to which SP was
entitled to under the Supply Agreement by the then-current market price. This figure
was then multiplied by SP’s most recent eighteen month profit margin of 35 percent,
which was confirmed before trial by actual performance from January 2005 through
June 2006. Based on this evidence, we conclude that the jury’s award was adequately
supported by the record.




                                         -16-
                                           2.

      Zoltek argues that the district court erred by allowing SP to present to the jury
a damages calculation that did not count $13,353,696 worth of Panex 35 toward the
maximum volume SP was allegedly entitled to under the Supply Agreement. This
amount reflected a quantity of Panex 35 purchased from Zoltek in 2006 and provided
to a wind energy manufacturer, Gamesa, under a sales contract between Zoltek and
Gamesa. The contract allowed Gamesa to specify a prepreg processor, and Gamesa
chose SP. Because SP received fiber from Zoltek in connection with the Gamesa
contract, Zoltek argues that the shipment under this contract should have been
subtracted from the maximum volume of Panex to which SP was entitled under the
Supply Agreement. SP counters that the shipment was processed pursuant to
Gamesa’s separate contractual right, not SP’s contractual right under the Supply
Agreement, and therefore should be excluded from the volume allowed under the
Supply Agreement. Zoltek also argues that it was prejudiced when the district court
allowed SP’s to change its proposed damages calculation twenty-two days before trial
by removing an offset for the amount of the Gamesa contract.

       The district court allowed SP to submit alternative damages figures, one that
counted the $13,353,696 Gamesa shipment toward the maximum quantity allowed
under the Supply Agreement, and one that did not. The jury adopted the larger figure.
Zoltek moved to reduce the award by $13,353,696 as a matter of law, but the district
court ruled that the sale to Gamesa had “no bearing on [Zoltek’s] obligation to provide
carbon fiber to [SP] under the Supply Agreement.”

       We first conclude that the district court did not abuse its discretion in rejecting
Zoltek’s objection to the timeliness of SP’s alternative damages calculation. In Phil
Crowley Steel Corp. v. Macomber, Inc., 

(8th Cir. 1979), this court held
that a district court did not abuse its discretion by allowing a change in the formula
used to calculate damages four days before trial, because “the documents upon which

                                          -17-
[the plaintiff’s] damages were calculated were made available to [the defendant] well
in advance of trial,” and because the defendant failed to seek a continuance after being
notified of the change in the formula. 

Similarly here, we see no prejudice
to Zoltek and no abuse of discretion. The Gamesa contract was incorporated into
Smith’s first report on damages; in that version, the amount was deducted from the
lost profits to which SP claimed that it was entitled. The revised report merely
changed that assumption and projected the lost profits without applying an offset for
Gamesa. The underlying information was available to Zoltek throughout, and Zoltek
had adequate opportunity to argue why it believed that the amount of the Gamesa
contract should offset any damages that the jury awarded under the requirements
contract.

       We also are not persuaded that the amount of the Gamesa contract must be
excluded as a matter of law from the jury’s final award to SP. The jury determined
that the volume of carbon fiber sold to Gamesa and processed by SP was not sold
pursuant to a right created under the Supply Agreement. The jury’s verdict in this
respect was adequately supported by the record. There was evidence that SP was not
a party to the Gamesa contract, was not involved in negotiating the contract, had no
say over the price or quantity shipped, and was obligated to transfer the product to
Gamesa after processing it. Zoltek’s CEO similarly testified at one point that the
shipment was made pursuant to Gamesa’s contractual right and “not to fulfill any
contractual commitment to SP.” The evidence adequately supported the jury’s
decision to find that Zoltek’s breach of the requirements contract extended to the full
amount to which SP was entitled under that contract, without regard to the separate
Gamesa contract.

                                           3.

      Finally, Zoltek argues that the district court’s damages instruction to the jury
did not “fairly and adequately present the applicable Missouri law of lost profits.”

                                         -18-
The district court instructed the jury that if it found in favor of SP on its claim for
breach of the supply agreement, then it must award the plaintiffs such sums as “you
believe will fairly and justly compensate them for any damages you believed they
sustained (and are reasonably certain to sustain in the future) as a direct result of
Zoltek’s breach of the Supply Agreement.” Zoltek complains that the instruction
should have included a specific direction not to award speculative damages, and that
the requirement of “reasonable certainty” should have applied to damages already
sustained, as well as damages to be sustained in the future.

       We review a district court’s jury instructions for an abuse of discretion. Black
v. Shultz, 

, 708 (8th Cir. 2008). To instruct the jury on damages, the
district court used Instruction No. 4.01 of the Missouri Approved Instructions (MAI)
for civil cases, which the Supreme Court of Missouri has described as “a short, simple,
general instruction which directs an award which will fairly compensate plaintiffs for
their damages.” Boten v. Brecklein, 

, 93 (Mo. 1970). We have rejected
another challenge to the verbatim use of MAI 4.01, holding that “[w]here the charge
to the jury correctly sets forth the law, a lack of perfect clarity will not render the
charge erroneous.” Roth v. Black & Decker, U.S., Inc., 

, 783-84 (8th Cir.
1984). We are not persuaded that the damages instruction in this case was flawed.
Given the specific direction that future damages must be “reasonably certain,” we see
no reasonable likelihood that a jury would have understood that present damages for
loss profits could be established by some lesser degree of certainty or by speculation.
We are satisfied that the instruction accurately sets forth Missouri law and was
sufficiently clear to give the jury appropriate direction.

                                         III.

     In its cross-appeal, SP argues that the district court erred by granting Zoltek’s
motion to alter or amend judgment pursuant to Federal Rule of Civil Procedure 59(e).
The verdict form submitted to the jury included alternative damages calculations

                                         -19-
corresponding to 3,000,000 pounds of Panex 33 and 3,960,276 pounds of Panex 35.
The jury awarded SP damages under both calculations. The district court concluded
that SP had argued throughout the case that the Supply Agreement entitled them to
“either Panex 33 or Panex 35,” but not to both, and therefore vacated the lesser of the
two awards as duplicative.

       We conclude that the district court did not abuse its discretion. SP’s complaint
pleaded Counts I and II in the alternative, demanding that Zoltek “supply the
unfulfilled quantities of PANEX 35 or, in the alternative, PANEX 33,” and alleging
that the contract was modified to “substitute” Panex 35 for Panex 33. SP’s damages
expert presented “alternative” damages calculations – one that assumed the Supply
Agreement encompassed both Panex 33 and Panex 35, and a second that assumed that
only Panex 33 was covered. The Supply Agreement referred to Panex 33 only, and
established a maximum quantity that SP was entitled to order. The jury evidently
accepted SP’s contention that it also was entitled to order Panex 35 under the
agreement, because it was an improved version of Panex 33, but the agreement did not
provide that SP could order the maximum quantity of both Panex 33 and Panex 35.



       Under the Supply Agreement, SP was entitled to order the quantity of carbon
fiber ordered in the immediately preceding year, plus one million pounds. Thus,
between 2004 and 2005, SP was entitled either to 3,960,276 pounds of Panex 35, or
3,000,000 pounds of Panex 33, but not both. The jury’s award under both Count I and
Count II gave SP profit corresponding to 6,960,276 pounds of large-tow carbon fiber
when at most SP was entitled to 3,960,276 pounds. Therefore, the district court acted




                                         -20-
within its discretion when it determined that the jury’s award under both counts was
duplicative and altered the judgment accordingly.

                                  *       *      *

      For these reasons, the judgment of the district court is affirmed.
                      ______________________________




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