FOR PUBLICATION
 UNITED STATES COURT OF APPEALS
      FOR THE NINTH CIRCUIT

UNITED STATES OF AMERICA,                  No. 03-10029
                Plaintiff-Appellee,
               v.                            D.C. No.
                                          CR-01-20173-RMW
ATUL BHAGAT,
                                              OPINION
             Defendant-Appellant.
                                      
       Appeal from the United States District Court
         for the Northern District of California
       Ronald M. Whyte, District Judge, Presiding

                  Argued and Submitted
        April 12, 2004—San Francisco, California
        Submission Withdrawn September 1, 2004
                Resubmitted July 6, 2005

                  Filed February 8, 2006

         Before: Mary M. Schroeder, Chief Judge,
      A. Wallace Tashima, and Johnnie B. Rawlinson,
                     Circuit Judges.

               Opinion by Judge Rawlinson;
                Dissent by Judge Tashima




                           1415
1418              UNITED STATES v. BHAGAT


                       COUNSEL

Mary McNamara, Swanson & McNamara LLP, San Fran-
cisco, California, for the defendant-appellant.

Amber S. Rosen, Assistant United States Attorney, San Jose,
California, for the plaintiff-appellee.
                     UNITED STATES v. BHAGAT                   1419
                            OPINION

RAWLINSON, Circuit Judge:

   Appellant Atul Bhagat (Bhagat) challenges his convictions
for insider trading; for securities tipping; and for obstructing
the course of an SEC investigation.1

  Because any new factual theory referenced by the govern-
ment during closing arguments was introduced for the proper
purpose of impeaching Bhagat’s credibility, and did not effect
a constructive amendment or material variance of the indict-
ment; the instructions conveyed all of the elements needed to
obtain a conviction on the obstruction charge; and sufficient
evidence supports Bhagat’s conviction, we affirm the judg-
ment of conviction.

  Because the court determined the amount of profit under a
mandatory guidelines system, we remand the sentence pursu-
ant to United States v. Ameline, 

(9th Cir. 2005)
(en banc).

I.       FACTUAL and PROCEDURAL BACKGROUND

   Bhagat’s employer, Nvidia Corporation (Nvidia), success-
fully competed for a multi-million dollar contract to develop
a video game console (the X-Box) for the Microsoft Corpora-
tion. Upon receiving the contract, Nvidia’s Chief Executive
Officer (CEO) sent a company-wide e-mail late Sunday night
announcing the contract award. The next morning, Nvidia
sent a number of follow-up e-mails. The first e-mail advised
Nvidia employees that the X-Box information should be kept
confidential. The other e-mails imposed a trading blackout on
the purchase of Nvidia stock for several days, and required
     1
   The government has withdrawn its cross-appeal challenging the sen-
tence imposed.
1420              UNITED STATES v. BHAGAT
Nvidia’s employees to cancel any open or outstanding orders
for Nvidia stock.

  A.   Insider Trading Allegations Against Bhagat

   The government’s theory of prosecution was that Bhagat
read the CEO’s Sunday night e-mail prior to purchasing
Nvidia stock. To support this theory, the government intro-
duced evidence that Bhagat arrived at work on Monday mid-
morning, and that all of the company-wide e-mails were on
his computer. The government also introduced evidence that
roughly twenty minutes after the final company-wide e-mail
was sent, Bhagat purchased a large quantity of Nvidia stock
— his largest purchase in nearly three years. There was no
direct evidence that Bhagat read any of the e-mail prior to
executing his purchase. Instead, the government asked the
jury to infer Bhagat’s knowledge by virtue of the fact that he
had probably read the original e-mail upon entering the office
as a “normal, reasonable person” would.

   Evidence was also presented that rumors about Nvidia and
the X-Box contract began leaking in the industry the day after
Bhagat purchased his stock, and the price of the stock rose
sharply. Three days later, the news was made public and the
price of Nvidia stock skyrocketed. Another four days later,
Bhagat sold his stock, reaping a substantial profit.

   Bhagat offered a different interpretation of the facts. He
testified to conducting personal business for several hours
upon reaching the office, and reading the company-wide e-
mails at 1:00 p.m. — roughly forty minutes after he purchased
the stock. Upon learning of the trading blackout, Bhagat
attempted to cancel his trade by contacting his broker, who
advised him that it was too late. However, Bhagat could not
remember which branch of the trading company he contacted,
nor the name, or even the gender, of the representative to
whom he spoke. Bhagat made no further attempt to divest
himself of the stock. He concluded that to do so would further
                   UNITED STATES v. BHAGAT                 1421
violate the trading blackout, although he sought no guidance
from any Nvidia executive regarding his failure to cancel his
pending trade.

   To rebut the government’s contention that his purchase of
Nvidia stock was motivated by insider information, Bhagat
testified that he purchased the stock after considering the gen-
eral strength of the stock, and with the expectation that the
company would win the X-Box contract. Bhagat introduced
evidence that he was a consistent purchaser of technology-
based stock. To counter the inference that he read the X-Box
e-mail before executing his trades, Bhagat introduced evi-
dence that, in a one-month period, he often did not send e-
mails until after 1:00 p.m.

  B.   Tipping Allegations Against Bhagat

   The prosecution sought to prove that Bhagat advised two
friends to buy Nvidia stock before the X-Box information was
officially released to the public. Less than one-half hour after
Bhagat made his purchase, two of his friends, Puneet
Mehrotra (Mehrotra) and Mamat Gill (Gill), purchased Nvidia
stock. There was no direct evidence that Bhagat contacted
Mehrotra or Gill prior to their purchases. However, Bhagat
did send Gill an e-mail during the blackout period, the day
after Gill purchased the Nvidia stock, containing a link to an
internet article discussing Nvidia and the X-Box. Evidence
was also introduced that Bhagat provided his real estate agent
with the X-Box information before it was made public.
Finally, Gill’s purchase was his largest purchase of the year.

  Bhagat denied telling anyone about the X-Box contract
before it was made public. He countered the prosecution’s
evidence with the argument that a friend of Gill’s, who
worked for one of Nvidia’s competitors, may have informed
Gill of the X-Box contract award.
1422                UNITED STATES v. BHAGAT
  C.   Reasons for the Increase in Nvidia’s Stock Price

   The parties disagree as to the reasons Nvidia’s stock price
increased between the time of Bhagat’s purchase and the time
the contract award was officially announced. The govern-
ment’s expert opined that the increase was primarily caused
by rumors regarding Nvidia and the X-Box contract. Bhagat
countered that the value of Nvidia’s stock rose during this
period primarily because Standard & Poor’s (S&P) issued a
listing announcement indicating that Nvidia was now part of
an S&P stock index.

   A number of witnesses, including Nvidia’s CEO and a
financial analyst, testified that stock prices generally rise after
a listing announcement. The government’s expert confirmed
the existence of studies showing that technology-based stocks
increase in value by ten percent after becoming listed. How-
ever, the expert qualified this observation by noting that the
ten percent increase represented the aggregate increase over
the course of several days to a few weeks. In light of Nvidia’s
past performances upon becoming listed in other indices, the
expert opined that it was highly unlikely that the listing
announcement in this case had such an immediate impact on
the market. Thus, according to the expert, any price increases
during this time were more likely attributable to the X-Box
rumors, and not to the listing announcement.

  D.   Trial Proceedings

   Bhagat was charged with insider trading, tipping, and
obstructing an SEC investigation. The most hotly contested
issue was whether the government adequately proved that
Bhagat possessed prior knowledge of the X-Box contract
award. The key provisions of the indictment are as follows:

      5. On . . . March 5 . . . NVIDIA entered into a
    contract with Mircrosoft to develop . . . a . . . proces-
    sor for . . . the “X-Box.”
                    UNITED STATES v. BHAGAT                  1423
       6. On Sunday, March 5 . . . NVIDIA’s president
    . . . sent an e-mail message to all NVIDIA employ-
    ees, including BHAGAT, announcing the contract.
    The e-mail . . . predicted that “[i]f Xbox becomes as
    big as Sony Playstation, we generate about $2B in
    sales over 5 years.”

       7. On Monday, March 6 . . . , at 9:15 . . .
    NVIDIA’s Vice President of Marketing sent an e-
    mail to all NVIDIA employees. The e-mail was enti-
    tled “xbox shhhhhh . . .” and said:

         . . . keep the xbox news quiet . . . . Mircro-
         soft plans to make the news public this Fri-
         day . . . [L]ets don’t jinx it!

       8. On March 6 . . . at . . . 12:23 . . . BHAGAT
    placed a market order to purchase 1000 shares of
    NVIDIA stock.

   The principal theory of the prosecution during the trial was
that Bhagat knew about the contract from reading his own e-
mail. During cross-examination, however, the prosecutor also
questioned Bhagat about conversations among his co-workers
that he had heard that morning concerning the X-Box con-
tract. This line of questioning set the stage for what the parties
refer to as the “office ‘abuzz’ theory.”

   Defense counsel informed the court that because the indict-
ment did not include an allegation that Bhagat learned about
the X-Box contract through office conversation, that theory
should not be permitted as part of the government’s case. In
the alternative, defense counsel requested an instruction
informing the jury that the mere existence of an open cubicle
environment may not, standing alone, give rise to an inference
that Bhagat possessed insider information. Ultimately, the
court authorized the government to present the argument, and
declined to give the requested instruction.
1424                  UNITED STATES v. BHAGAT
   During closing arguments, the government referenced the
“office abuzz” theory in passing, stating that the jury should
consider the fact that the office was “abuzz” with the news of
the X-Box contract, and that Bhagat had to walk through the
office to reach his cubicle. The government also repeatedly
informed the jury that in order to find Bhagat guilty, the gov-
ernment would have to prove that he read the company-wide
e-mails prior to purchasing the stock.

   The jury convicted Bhagat of insider trading, of tipping
Gill, and of obstructing an SEC investigation by making false
statements to SEC investigators.

  E.    Sentencing Proceedings

    The district court calculated the “total increase in value”
attributable to Bhagat and his tippee. See U.S.S.G. § 2F1.2,
Background Note (1998).2 The district court measured Bha-
gat’s profit by finding the difference between the price Bhagat
and Gill paid for the stock, and the price at which they sold
it. When combined, the pair’s profits exceeded sixty thousand
dollars, thereby triggering a five-level sentencing enhance-
ment. U.S.S.G. § 2Fl.1(b)(1).

  F.    Post-trial Motions

  Bhagat moved for acquittal on the basis of insufficient evi-
dence. In the alternative, he sought a new trial on the same
grounds he asserts in this appeal. The district court denied
Bhagat’s motions and Bhagat timely appealed.
  2
   Although Bhagat was sentenced in 2003, the district court applied the
1998 version of the Sentencing Guidelines to avoid any ex post facto prob-
lems.
                     UNITED STATES v. BHAGAT              1425
II.    DISCUSSION

  A.       Standards of Review

   The district court’s decision to deny a motion for a new
trial is reviewed for an abuse of discretion. United States v.
Peterson, 

, 821 (9th Cir. 1998). The decision to
deny a motion for acquittal is reviewed de novo. United States
v. Johnson, 

, 983 (9th Cir. 2004). Allegations of
constructive amendment or material variance are also
reviewed de novo. United States v. Adamson, 

,
612, 616 (9th Cir. 2002).

  B.       Constructive Amendment or Material Variance

  A constructive amendment mandates per se reversal, how-
ever, a variance warrants reversal only if the defendant’s
“substantial rights” were affected. 

      1.    Constructive Amendment

   [1] A constructive amendment exists if “there is a complex
of facts presented at trial distinctly different from those set
forth in the [indictment],” or if “the crime charged in the
indictment was substantially altered at trial, so that it was
impossible to know whether the grand jury would have
indicted for the crime actually proved.” 

(citations
and alterations omitted).

   Bhagat contends that the government’s reference to the “of-
fice abuzz” theory introduced an alternative theory by which
the jury could infer Bhagat’s knowledge of the X-Box con-
tract prior to the stock transaction. The government counters
that it invoked the “office abuzz” theory for the limited pur-
pose of impeaching Bhagat’s credibility when he testified that
he had not heard anyone mention the X-Box contract upon
entering the office on Monday morning.
1426                   UNITED STATES v. BHAGAT
   The government’s conduct throughout the trial is consistent
with its contention. The government repeatedly informed the
jury that conviction should be based upon a determination that
Bhagat had read the company-wide e-mails prior to executing
his trades. It was only during cross-examination, after Bhagat
denied reading the pertinent e-mails, that the government
questioned Bhagat about whether he had heard any office
chatter regarding the X-Box contract.

   The district court judge, who heard the testimony at issue,
denied the defense request to give an instruction regarding an
“open cubicle” environment. The district court also permitted
the government to include in its closing argument reference to
Bhagat’s work environment for the purpose of challenging
Bhagat’s credibility.3 After the prosecutor expressly men-
tioned credibility, he immediately segued into the “office
abuzz” reference. The district court overruled the defense
objection, stating that “one can argue inferences. Whether
they’re reasonable inferences, that’s up to the jury.”

   [2] We have previously held that evidence not referenced
in the indictment may be admitted for “impeachment or other
legitimate purposes,” without effecting any changes to the
indictment. United States v. Kahan & Lessin Co., 

, 1125 (9th Cir. 1982). The record in this case reflects
that the reference to the “office abuzz” theory was not
intended to and did not amend the indictment. The facts pre-
   3
     “It is the province of the trier of fact ‘to determine the credibility of
witnesses, resolve evidentiary conflicts, and draw reasonable inferences
from proven facts.’ ” United States v. Magallon-Jimenez, 

,
1114 (9th Cir. 2000) (citation omitted). A reasonable inference could be
drawn that Bhagat was not credible when he denied hearing about the X-
Box contract despite the “cubicle configuration” of his workplace. And, of
course, if Bhagat was not credible on that point, the jury could also find
a lack of credibility as to his testimony regarding reading the e-mails. See,
e.g., Sea Hawk Seafoods, Inc. v. Alyeska Pipeline Serv. Co., 

,
912 (9th Cir. 2000) (“It is logical to disbelieve even a plausible allegation
if a witness makes it in the course of a generally implausible account.”).
                    UNITED STATES v. BHAGAT                  1427
sented were not “distinctly different” from those in the indict-
ment. Neither was “the crime charged in the indictment . . .
substantially altered at trial.” 

(cita-
tions and alterations omitted). That being so, no constructive
amendment of the indictment occurred. Rather, the evidence
was admitted for impeachment purposes, a practice we
expressly approved in Kahan & Lessin 

.

    2.   Material Variance

   [3] A material variance exists if a materially different set of
facts from those alleged in the indictment is presented at trial,
and if that variance affects the defendant’s “substantial
rights.” 

-16.

   In Adamson, we concluded that there was a variance
between the indictment and the proof at trial because the
“misrepresentation specified in the indictment and the misrep-
resentation shown at trial” differed. 

The misrepre-
sentation charged in the indictment was the fact that computer
servers had been upgraded. The court’s instructions, however,
allowed the jury to find the defendant guilty based on a mis-
representation regarding how the servers were upgraded. 

that there was a variance because there was
“but one set of facts with a single divergence, namely, the
content of the misrepresentation that the defendant made.” 

quotation marks and citation omitted).

   [4] No similar situation exists in this case. At all times, the
pertinent fact was that Bhagat was aware of the e-mails noti-
fying employees of the X-Box contract award. Not only was
there no jury instruction given regarding the “office abuzz”
notion, the district court judge expressly declined to give a
related instruction requested by defense counsel. The record
does not support a claim of variance.

   Bhagat’s reliance on United States v. Choy, 

(9th Cir. 2002), is misplaced. In Choy, the defendant was
1428               UNITED STATES v. BHAGAT
indicted for giving $5,000 to a public official. However, he
was convicted “on the theory that giving the $5,000 to a pri-
vate individual indirectly conferred value — the opportunity
to receive bribes in the future — on a public official.” 

. We found a fatal variance because the “facts
upon which Choy was convicted cannot constitute the crime
[of bribery].” 

concluded that the jury instructions
and clarification enabled the jury to base a finding of guilt on
a fact other than the element stated in the indictment. 

As in Adamson, in Choy we focused on the extent to
which the jury was steered toward a finding at variance with
the indictment. See 

, see also 

-16. Nothing of the sort occurred in this case,
and the verdict reflected no material variance from the
charges in the indictment.

  C.   Jury Instruction for Obstructing an Agency
       Proceeding

   [5] Bhagat was convicted under 18 U.S.C. § 1505 for the
crime of obstructing an SEC investigative proceeding by mak-
ing false statements to SEC investigators. The government
was required to prove three elements: (1) that there was an
agency proceeding; (2) that the defendant was aware of that
proceeding; and (3) that the defendant “intentionally endeav-
ored corruptly to influence, obstruct or impede the pending
proceeding.” United States v. Price, 

, 1031 (9th
Cir. 1991) (citation omitted). Because Bhagat failed to object
to the instructions as given, we review for plain error. United
States v. Delgado, 

, 1065 (9th Cir. 2004).

   Bhagat contends that the Supreme Court’s decision in
United States v. Aguilar, 

, 599-601 (1995),
added two additional elements going to mens rea: that his
false statements must have the “natural and probable effect”
of obstructing justice, and that he was aware of that effect.
Bhagat asserts that we recognized the applicability of Aguilar
to Section 1505 proceedings in our decision in United States
                      UNITED STATES v. BHAGAT                        1429
v. Hopper, 

, 830-31 (9th Cir. 1999). We dis-
agree.

   [6] Aguilar did not involve obstruction of agency proceed-
ings under 18 U.S.C. § 1505. Rather, the court in Aguilar
addressed false statements made during the course of an agen-
cy’s investigative proceeding that obstructed a judicial pro-
ceeding pursuant to 18 U.S.C. § 1503’s “catchall” provision.4
The Supreme Court noted that judicial proceedings are dis-
tinct from government investigations, and that the intent to
obstruct an agency proceeding did not automatically demon-
strate intent to obstruct the related judicial one. See 

. To transpose the intent to obstruct an
agency proceeding into the judicial proceeding context, the
Court held that there had to be a “nexus” between the two
proceedings. 

The Court then held that the jury
could infer the existence of that nexus if the “natural and
probable effect” of the defendant’s conduct vis á vis the
agency proceeding would obstruct justice. 

Bhagat was charged under Section 1505 with
obstructing an agency proceeding and not a judicial one, there
was no need to create a causal nexus and, consequently, no
need to supplement the Price instructions with additional ele-
ments. Cf. United States v. Gabriel, 

, 103-04 (2d
Cir. 1997) (declining to incorporate a nexus requirement into
18 U.S.C. § 1512(b), the witness tampering statute); 

& n.2 (distinguishing Aguilar from cases
where false statements were made directly in the relevant pro-
ceedings).

   Bhagat’s reliance on 

, fails for
  4
    18 U.S.C. § 1503 contains a “catchall” provision prohibiting the
obstruction of “the due administration of justice.” That provision has been
interpreted as encompassing judicial proceedings. See, e.g., 

; United States v. Veal, 

, 1250 (11th Cir.
1998).
1430               UNITED STATES v. BHAGAT
similar reasons. In Hopper, the defendants were charged with
obstructing the IRS’s attempt to collect on a tax judgment. 

The Hopper defendants argued that they were wrong-
fully charged under 18 U.S.C. § 1505, because their interfer-
ence was with a court judgment, not an agency proceeding.

Aguilar, we disagreed, stating that the defen-
dants’ attempt to avoid payment of the tax would have the
“probable and natural effect” of interfering with the IRS’s
attempt to collect taxes. 

Aguilar’s “natural and
probable effect” language to explain how the defendants’ con-
duct affected the IRS’s collection proceeding, not to add an
additional element of proof.

  [8] Because the provided jury instructions adequately
addressed the elements needed to obtain a conviction under
18 U.S.C. § 1505, Bhagat is not entitled to a new trial on this
basis.

  D.     Sufficiency of the Evidence

   Evidence is sufficient to support a conviction if, consider-
ing the evidence in the light most favorable to the prosecu-
tion, any reasonable juror could have found the essential
elements of the offense beyond a reasonable doubt. United
States v. Matthews, 

, 814 (9th Cir. 2001). For the
following reasons, we hold that sufficient evidence supported
Bhagat’s convictions on all grounds.

    1.    Insider Trading

  [9] To convict Bhagat of insider trading, the government
was required to prove that he “traded stock on the basis of
material, nonpublic information.” United States v. Henke, 

, 639 (9th Cir. 2000).

  [10] The government offered significant evidence to sup-
port the jury’s conclusion that Bhagat was aware of the confi-
dential X-Box information before he executed his trades. The
                      UNITED STATES v. BHAGAT                       1431
X-Box e-mails were sent prior to his purchase. The e-mails
were found on his computer. Bhagat was at his office for sev-
eral hours prior to executing his trade, which provided him
the opportunity to read the e-mails. Finally, Bhagat took virtu-
ally no action to divest himself of the stock, or to inform his
company that he had violated the company’s trading blackout.
The fact that this evidence was all circumstantial does not
lessen its sufficiency to support a guilty verdict. See United
States v. Messer, 

, 343 (9th Cir. 1999).

      2.   Obstructing an Agency Proceeding

  To convict Bhagat for obstructing an agency proceeding
pursuant to 18 U.S.C. § 1505, the government was required to
prove that an agency of the United States government was
conducting a proceeding; that the defendant was aware of that
proceeding; and that the defendant intentionally interfered
with, or obstructed the course of, that proceeding. 

.

   [11] Sufficient evidence also supports the jury’s verdict on
this charge. It is undisputed that there was an SEC investiga-
tive proceeding of which Bhagat was aware. The prosecution
also introduced evidence that Bhagat intentionally obstructed
that proceeding by providing the SEC investigators with false
information to cover up his acts of insider trading and tipping
and eliminate himself as a suspect.5 Cf. United States v.
Boone, 

, 1233-34 (9th Cir. 2000) (quoting from
Lilly v. Virginia, 

, 139 (1999)) (criminal suspects
have a “natural motive to attempt to exculpate [themselves] as
much as possible” while being questioned by law enforce-
ment). No relief is warranted on this ground.
  5
    This testimony included Bhagat’s denying knowing anyone who pur-
chased Nvidia securities during the week of the X-Box contract award and
denying informing anyone outside of Nvidia of the contract award. Spe-
cific evidence to the contrary was introduced at trial by the prosecution.
1432                     UNITED STATES v. BHAGAT
       3.    Tipping

  To convict Bhagat of tipping Gill, the government was
required to prove that the tipper, Bhagat, provided the tippee,
Gill, with material, inside information, prior to the tippee’s
purchase of stock. See United States v. O’Hagan, 

, 675 (1997).

   [12] Viewing the evidence in the light most favorable to the
prosecution, we cannot say that no reasonable trier of fact
could have found Bhagat guilty. Bhagat and Gill were friends;
Bhagat had provided inside information to his real estate bro-
ker, with whom he shared a more distant relationship; Gill
purchased stock shortly after Bhagat; and Gill’s purchase was
his largest purchase of the year. See United States v. Larra-
bee, 

, 21-22 (1st Cir. 2001) (listing relevant fac-
tors).

  E.        Sentencing

   [13] Bhagat challenges the method used by the district
court to calculate his gains. Because the district court’s sen-
tencing determinations were made under the then-mandatory
Sentencing Guidelines, we remand for limited reconsideration
under Ameline. See United States v. Moreno-Hernandez, No.
03-30387, 

, at *9 (9th Cir. July 5, 2005)
(“conclud[ing] that a limited remand is proper in all pending
direct criminal appeals involving unpreserved Booker error.”)
(emphasis in the original).

III.    CONCLUSION

  The government’s use of the “office abuzz” theory did not
constructively amend the indictment or create a material vari-
ance between the facts alleged in the indictment and the evi-
dence presented at trial.

  The district court provided adequate jury instructions on the
charge of obstructing an agency proceeding.
                     UNITED STATES v. BHAGAT                     1433
  Sufficient evidence supported Bhagat’s convictions on all
counts.

  A limited remand of Bhagat’s sentence under Ameline is
appropriate.6

 CONVICTION AFFIRMED, SENTENCE
REMANDED.



TASHIMA, Circuit Judge, dissenting:

   Atul Bhagat (“Defendant”) was charged in a seven-count
indictment with: (1) securities fraud (insider trading) in viola-
tion of 15 U.S.C. §§ 78j, 78ff, and 17 C.F.R. § 240.10b-5
(Counts One and Two); (2) making false statements to the
Securities and Exchange Commission (“SEC”) in violation of
18 U.S.C. § 1001 (Counts Three, Four, Five, and Six); and (3)
obstruction of justice in violation of 18 U.S.C. § 1501 by pro-
viding false information in an SEC investigation (Count
Seven). After a trial by jury, Defendant was convicted of all
counts, except Count Four.

  Defendant is an engineer and was employed by NVIDIA
Corporation, a Silicon Valley manufacturer of graphics pro-
cessor and media communications devices. On March 5,
2000, NVIDIA entered into a contract with Microsoft to
develop and manufacture a 3-D graphics processor for Micro-
soft’s new video game console, the “X-Box.” As to how
Defendant obtained insider information about that contract,
paragraphs 6 and 7 of the indictment alleged:

        6. On Sunday, March 5, 2000, at 11:04 p.m.
      PST, NVIDIA’s president and chief executive offi-
  6
   In view of this ruling, Bhagat’s Motion for Supplemental Briefing is
denied as moot.
1434               UNITED STATES v. BHAGAT
    cer sent an e-mail message to all NVIDIA employ-
    ees, including BHAGAT, announcing the contract.
    The e-mail said that NVIDIA had obtained the X-
    Box contract from Microsoft. The e-mail revealed
    that Microsoft would “prepay” NVIDIA $200 mil-
    lion and predicted that “[i]f Xbox becomes as big as
    Sony Playstation, we generate about $2B in sales
    over 5 years.”

      7. On Monday, March 6, 2000, at 9:15 a.m.
    PST, NVIDIA’s Vice President of Marketing sent an
    e-mail to all NVIDIA employees. The e-mail was
    entitled “xbox shhhhhh . . .” and said:

       [The NVIDIA CEO] called me a few minutes ago
       (he is travelling) and asked that i remind everyone
       to keep xbox news quiet. Not a word to anyone
       outside of our walls. Lets let the news roll out in
       a controlled way. Microsoft plans to make the
       news public this Friday at GDC. But anything can
       happen; lets don’t jinx it!

The indictment then charged, and Defendant does not contest,
that later the same day (at 12:23 p.m.), he purchased 1,000
shares of NVIDIA stock at 61-3/4 and 61-7/8 per share. The
contract was publically announced on March 10 and NVIDIA
stock immediately and substantially increased in price. Defen-
dant sold his shares for $110,000, reaping a profit in excess
of $48,000.

   The government’s initial theory, consistent with the indict-
ment, was that Defendant read the e-mails when he arrived at
work that Monday morning, but there is no direct evidence
that he did so. Defendant denied that he read the e-mails
before placing his buy order and testified that he did not read
                      UNITED STATES v. BHAGAT                     1435
them until 1:00 p.m., approximately 40 minutes after he made
his purchase.1

   During its cross-examination of Defendant, the government
pursued what the parties refer to as the “office abuzz” theory.
The government’s questioning of Defendant suggested that
because of the open cubicle configuration of the office,
Defendant could not help but overhear conversations among
his co-workers regarding the exciting news of the X-Box con-
tract — that the office was “abuzz” with the news. Defendant
denied that he overheard any X-Box office conversation. The
district court overruled Defendant’s objection that the govern-
ment should not be allowed to argue the “office abuzz” theory
because “there is no evidence in the record the company was
abuzz with the news,” as indeed there was not, as a basis of
liability. It also rejected Defendant’s proffered instruction that
“the mere existence of an open cubicle environment may not,
standing alone, give rise to an inference that Bhagat possessed
insider information.”

   Given that latitude, the government argued in closing that
even if the jury could not infer that Defendant obtained
insider information from the e-mails, it could draw that infer-
ence from the fact that the office was “abuzz” with informa-
tion about the X-Box contract. Specifically, the prosecutor
argued “[i]n terms of whether Bhagat possessed the informa-
tion, you should consider the magnitude of this news. This
was big, big, big news. The company [was] abuzz with this
news.” The prosecutor then walked the jury through the evi-
dence that he claimed supported the “office abuzz” theory of
liability:

      He [Defendant] walked through the reception area,
      he sat in a room filled with people, with cubicles
      with no doors, he went to the cafeteria, and he says,
  1
   Defendant also testified that when he learned of the trading blackout
he attempted to cancel his trade, but was unsuccessful.
1436                     UNITED STATES v. BHAGAT
      you know, he walked around in a bubble and this big
      news didn’t reach him over the course of three hours
      with other people.

   This “office abuzz” theory of liability as to how Defendant
acquired insider information, an essential element of the
charged crime,2 is factually distinct from the theory charged
in the indictment, that Defendant acquired the insider infor-
mation through reading the company-wide e-mails. Because
it is a new, uncharged theory, Defendant had no notice of it
and no opportunity to defend against it, to rebut it with his
own evidence.3

   Thus, under our case law, this clearly is a case of a prejudi-
cial variance from the indictment which requires reversal.
This case is indistinguishable from United States v. Choy, 

(9th Cir. 2002). There the indictment charged that
Choy “gave, offered, and promised a thing of value (to wit,
$5,000.00) to a public official.” 

At trial, however,
the government advanced an uncharged theory that Choy pur-
chased computers to be used by a public official in a bribery
scheme. See 

The district court instructed the jury
that it could conclude that Choy “provided a thing of value”
under either the theory charged in the indictment or the theory
advanced at trial. 

because the new theory was
a variance that involved “a set of facts distinctly different
  2
     Although the acquisition of insider information is technically an ele-
ment only of the Count One charge — insider trading — factually, it is
an indispensable predicate of all of the remaining counts of conviction.
   3
     Accepting the government’s contention, the majority asserts that the
“office abuzz” theory was permitted to be “invoked” “for the limited pur-
pose of impeaching Bhagat’s credibility. . . .” Maj. op. at 1425. Yet, in
rejecting Defendant’s proposed instruction that this theory could not be a
basis of liability, the trial court failed to give a limiting instruction that this
theory, and any evidence in support of it, could be used only to assess
Defendant’s credibility and not as a basis of liability. Further, the govern-
ment’s closing argument, summarized above, belies its contention that the
theory was invoked solely to impeach Defendant’s credibility.
                    UNITED STATES v. BHAGAT                   1437
from that set forth in the indictment. 

So too here,
the “office abuzz” theory is a variance that involves “a set of
facts distinctly different from that set forth in the indictment.”

previously observed that “[o]ne of the primary
purposes of an indictment is to inform a defendant of ‘what
he is accused of doing in violation of the criminal law, so that
he can prepare his defense.’ ” United States v. Adamson, 

, 616 (9th Cir. 2002) (quoting United States v. Tsinh-
nahijinnie, 

, 991 (9th Cir. 1997)). As in Adam-
son:

       This purpose was not served here. If the indict-
    ment had not specified a different particular misrep-
    resentation, one might say the variance was benign.
    Having specified a different particular misrepresen-
    tation, however, the indictment not only failed to
    inform the defendant of the actual misrepresentation
    that would be shown at trial, but it also affirmatively
    misled the defendant and obstructed his defense at
    trial.

would conclude that the variance here
affected Defendant’s substantial rights and, thus, requires
reversal. See 

lip service to the rule that “[a] material vari-
ance exists if a materially different set of facts from those
alleged in the indictment is presented at trial, and if that vari-
ance affects the defendant’s ‘substantial rights’ ” (citing

-16), the majority elides the analy-
sis required by that rule and simply concludes that “[a]t all
times, the pertinent fact was that Bhagat was aware of the e-
mails notifying employees of the X-Box contract award.”
Maj. op. at 1427. Yet, that is precisely the determinative issue
that was hotly contested in this case. While it is uncontested
that the two company-wide e-mails were transmitted, there is
1438                UNITED STATES v. BHAGAT
no direct evidence that Defendant was “aware” of them;
indeed, he denied that he read his office e-mails until 1:00
p.m. on Monday. Thus, the majority conveniently jumps to a
conclusion that is unsupported by the record.

   The majority’s discussion of this issue concludes by noting
that “[a]s in Adamson, in Choy we focused on the extent to
which the jury was steered toward a finding at variance with
the indictment.” 

(citing 

;

-16). It then asserts that “[n]othing
of the sort occurred in this case, and the verdict reflected no
material variance from the charges in the indictment.” 

occurred in Adamson and Choy is exactly what occurred
in this case: By permitting the government to argue in closing
that insider liability could be predicated on the “office abuzz”
theory, “the jury was steered toward a finding [acquisition of
insider information] at variance with the indictment,” which
charged the acquisition of insider information solely from a
reading of the company-wide e-mails. And the majority’s
assertion that “the verdict reflected no material variance from
the charges in the indictment,” 

non sequiter. First, the
majority’s speculation of what the verdict may reflect is not
the test under our variance jurisprudence. Second, the very
reason for our variance jurisprudence is precisely because we
cannot know whether “the verdict reflected no material vari-
ance from the charges in the indictment.”

   I therefore respectfully dissent from the majority’s conclu-
sion that “[t]he record does not support a claim of variance,”

its holding affirming the judgment of conviction.