  United States Court of Appeals
      for the Federal Circuit
                 ______________________

      MONOLITHIC POWER SYSTEMS, INC.,
      Plaintiff/Counterclaim Defendant-Appellee,

                          AND

    ASUSTEK COMPUTER, INC., AND ASUSTEK
     COMPUTER INTERNATIONAL AMERICA,
        Counterclaim Defendants-Appellees,

                            v.

      O2 MICRO INTERNATIONAL LIMITED,
        Defendant/Counterclaimant-Appellant.
               ______________________

                       2012-1221
                 ______________________

   Appeal from the United States District Court for the
Northern District of California in No. 08-CV-4567, Judge
Claudia Wilken.
                ______________________

                Decided: August 13, 2013
                 ______________________

    DAN L. BAGATELL, Perkins Coie, LLP, of Phoenix, Ari-
zona, argued for plaintiff/counterclaim defendant-appellee
and counterclaim defendants-appellees. With him on the
brief were DEAN G. DUNLAVEY, Latham & Watkins, LLP,
of Costa Mesa, California, and MARK A. FLAGEL, of Los
2               MONOLITHIC POWER SYSTEMS, INC.   v. O2 MICRO
                                         INTERNATIONAL LTD.


Angeles, California, for plaintiff/counterclaim defendant-
appellee, Monolithic Power Systems, Inc.

    EDWARD R. REINES, Weil, Gotshal & Manges, LLP, of
Redwood Shores, California, argued for defend-
ant/counterclaimant-appellant. With him on the brief
was TIMOTHY C. SAULSBURY.
                ______________________

     Before PROST, MAYER, and REYNA, Circuit Judges.
PROST, Circuit Judge.
     O2 Micro International Ltd. (“O2 Micro”) appeals from
the decision of the United States District Court for the
Northern District of California finding this case exceptional
under 35 U.S.C. § 285 and awarding attorney fees and costs
to Monolithic Power Systems, Inc. (“MPS”), and ASUSTeK
Computer, Inc. and ASUSTeK Computer International
(collectively, “ASUSTeK”). See Monolithic Power Sys., Inc. v.
O2 Micro Int’l Ltd., No. 08-4567, 2011 U.S. Dist. LEXIS
154454 (N.D. Cal. Mar. 3, 2011) (“Exceptional Case Order”);
Monolithic Power Sys., Inc. v. O2 Micro Int’l Ltd., No. 08-
4567, 2012 U.S. Dist. LEXIS 5109 (N.D. Cal. Jan. 17, 2012)
(“Fees and Costs Order”). We affirm both the exceptional
case finding and the attorney fees award.
                        BACKGROUND
    MPS and O2 Micro are competitors in the market for in-
tegrated circuit products that control LCD and LED light-
ing. Both parties own many patents, a small subset of which
is at issue. ASUSTeK, an international hardware and
electronics manufacturer, is an MPS customer.
                   A. Previous Litigation
   For more than a decade, MPS and O2 Micro have been
embroiled in litigation. Not counting the suits filed against
MONOLITHIC POWER SYSTEMS, INC.   v. O2 MICRO               3
INTERNATIONAL LTD.


MPS customers in other district courts, there have been five
lawsuits in which O2 Micro asserted patent infringement
claims against MPS in the Northern District of California.
This case was the fifth.
    In October 2001, O2 Micro filed suit against MPS, alleg-
ing infringement of U.S. Patent No. 6,259,615. The district
court granted summary judgment of noninfringement in
favor of MPS. This decision was affirmed on appeal. O2
Micro Int’l Ltd. v. Monolithic Power Sys., Inc., 467 F.3d 1355
(Fed. Cir. 2006).
    In January 2003, O2 Micro filed an infringement suit
against an MPS customer in the Eastern District of Texas,
prompting MPS to file suit against O2 Micro in May 2004.
MPS sought declarations of noninfringement and invalidity
of O2 Micro’s U.S. Patent No. 6,396,722 (“’722 patent”). O2
Micro counterclaimed for infringement. Despite O2 Micro’s
efforts to overcome prior art by attempting to establish an
earlier date of conception, 1 a jury found the ’722 patent



    1    The key piece of prior art MPS used to invalidate
O2 Micro’s ’722 patent was the MP1010 circuit, an MPS
product designed in 1998 and used by MPS customers by
early 1999. The ’722 patent claimed priority to a provi-
sional application filed on July 22, 1999. To establish an
earlier invention date, O2 Micro proffered printouts of its
own schematics bearing the date stamp, “Feb., 18, 1998,”
which was in an unusual format with an extra comma
between “Feb.” and “18.” The schematics would serve to
corroborate O2 Micro’s assertion that inventor-engineer,
Dr. Yung-Lin Lin, had conceived of the subject matter
claimed in the ’722 patent by that date. See Exceptional
Case Order, at *5. At trial, Dr. Lin and an O2 Micro
executive both testified that the February 18, 1998 date
was automatically generated on the schematics by a
4               MONOLITHIC POWER SYSTEMS, INC.   v. O2 MICRO
                                         INTERNATIONAL LTD.


invalid based on obviousness and the on-sale bar. The
verdict was affirmed on appeal. Monolithic Power Sys., Inc.
v. O2 Micro Int’l Ltd., 558 F.3d 1341 (Fed. Cir. 2009).
    In October 2004, O2 Micro filed a lawsuit against two
other MPS customers in the Eastern District of Texas,
accusing them of infringing U.S. Patent No. 6,804,129 (“’129
patent”). The case was subsequently transferred to the
Northern District of California, and consolidated with MPS’s
suit filed in May 2004, discussed above. After the transfer,
O2 Micro withdrew from the case, covenanting not to sue
MPS and its two customers for infringement of the ’129
patent.
     In July 2005, O2 Micro asserted the ’129 patent again in
the Eastern District of Texas against a third MPS customer,
prompting MPS to file another declaratory judgment action
against O2 Micro in May 2007. O2 Micro fought the suit
with two motions to dismiss for lack of subject matter juris-
diction, but they were denied. O2 Micro then covenanted
not to sue MPS and its customers for infringement of the
’129 patent, and stipulated to the dismissal of the suit.
                   B. Current Litigation
    This brings us to the current litigation. In October
2008, MPS filed a declaratory judgment action against O2
Micro, seeking declarations of noninfringement and invalidi-
ty with respect to four related O2 Micro patents: U.S. Patent
Nos. 6,856,519, 6,809,938, 6,900,993, and 7,120,035 (“’519
patent family”). Before MPS served the complaint, but after
O2 Micro had learned of the lawsuit, O2 Micro had filed a
complaint in the International Trade Commission (“ITC”),
under § 337 of the Tariff Act of 1930, against MPS and its
customers, including ASUSTeK.         The § 337 complaint

software program used at O2 Micro. Id. at *6. This
turned out to be false in the case underlying this appeal.
MONOLITHIC POWER SYSTEMS, INC.   v. O2 MICRO               5
INTERNATIONAL LTD.


alleged that MPS’s and ASUSTeK’s imports infringed three
of the four patents in the ’519 patent family, as well as U.S.
Patent No. 7,417,382 (“’382 patent”). 2
    Soon thereafter, MPS amended the complaint to include
the ’382 patent and served O2 Micro. The next day, the ITC
notified the parties that it will be instituting an investiga-
tion.
    In the underlying district court action, O2 Micro coun-
terclaimed for infringement and added additional MPS
customers,     including    ASUSTeK,      as   counterclaim-
defendants. O2 Micro also filed a motion to stay the district
court proceedings pending resolution of the ITC investiga-
tion. In March 2009, the district court denied the motion in
favor of both proceedings moving forward in parallel. To
avoid duplication and a waste of resources, the district court
ordered that all discovery in the ITC proceeding would apply
in the district court action. Exceptional Case Order, at *8.
All parties assented to this procedure.




    2   The ’382 patent belongs to the same family as the
’722 patent, which was found invalid by a jury in the May
2004 lawsuit between O2 Micro and MPS. Because they
were part of the same family, the ’382 patent shared the
same priority date as the ’722 patent, based on the July
22, 1999 filing of a common provisional application. Thus,
O2 Micro faced the same hurdles with respect to invalidi-
ty in the ITC investigation and the case underlying this
appeal as it did in the May 2004 lawsuit. To defend
against assertions of invalidity based on prior art, O2
Micro again relied on Dr. Lin’s “Feb., 18, 1998” schematics
to attempt to establish a conception date before the date
the MP1010 circuit had been designed. See Exceptional
Case Order, at *9.
6               MONOLITHIC POWER SYSTEMS, INC.    v. O2 MICRO
                                         INTERNATIONAL LTD.


    Several months later, O2 Micro dismissed an MPS cus-
tomer from the district court suit and withdrew its assertion
of the ’519 patent family from both the district court and
ITC proceedings. In addition, O2 Micro covenanted not to
sue MPS or its customers for infringement of the ’519 patent
family. This left only the ’382 patent in the suit from July
2009 forward.
    It bears mentioning that throughout both the ITC inves-
tigation and the district court proceeding, O2 Micro insisted
that the ’382 patent is entitled to a February 18, 1998
conception date, as corroborated by the computer-generated
date on Dr. Lin’s schematics printout. As noted above, as in
the May 2004 litigation involving the ’722 patent, here the
schematics printout was O2 Micro’s best hope for overcom-
ing MPS’s invalidating art. Thus, O2 Micro filed multiple
verified interrogatories attesting to the same. Dr. Lin, the
inventor, testified in deposition and at trial in the ITC that
he conceived the invention claimed in the ’382 patent by
February 1998, as reflected by the computer-generated date
stamp on the schematics.
     However, O2 Micro’s story surrounding the schematics
unraveled when MPS served the report of its hired schemat-
ics expert, Marc Herniter, proving, inter alia, that the date
stamp on the schematics had been manually entered.
Thereafter, O2 Micro “dissembled” and “sought to mask its
proffer of false testimony.” Exceptional Case Order, at *20.
It supplemented its interrogatory responses; it moved to
strike Dr. Herniter’s report; and it moved for summary
adjudication to establish February 18, 1998 as the date of
conception of the subject matter claimed by the ’382 pa-
tent—all in an attempt to put the controversy surrounding
the “Feb., 18, 1998” schematics to rest.
   In February 2010, the district court ruled on the parties’
summary adjudication motions. O2 Micro’s motions for
summary adjudication concerning the authenticity of sche-
MONOLITHIC POWER SYSTEMS, INC.   v. O2 MICRO               7
INTERNATIONAL LTD.


matics and the invention date of the ’382 patent were de-
nied. MPS and ASUSTeK’s motion for summary adjudica-
tion that the earliest invention date for the ’382 patent was
July 22, 1999 was granted, as was their motion for summary
adjudication of lack of willfulness. Finally, MPS and ASUS-
TeK’s motions for summary judgment of invalidity and
noninfringement were denied. Monolithic Power Sys. v. O2
Micro Int’l Ltd., No. 08-4567, 2010 U.S. Dist. LEXIS 13106
(N.D. Cal. Feb. 12, 2010). Trial was set for July 2010. Id. at
*32.
     In May 2010, the district court appointed its own tech-
nical expert under Federal Rule of Evidence 706 to assist
with infringement and invalidity determinations. The court-
appointed expert’s June 15, 2010 opinion rejected O2 Micro’s
positions, concluding that all asserted claims of the ’382
patent were invalid, and either not infringed or likely not
infringed.
    Four days later, after MPS and ASUSTeK had filed
their pretrial submissions, O2 Micro granted them a cove-
nant not to sue on the ’382 patent and moved the district
court to dismiss the lawsuit. The district court dismissed all
claims with prejudice on June 23, 2010.
     On July 1, 2010, MPS and ASUSTeK moved for attorney
fees, costs, and sanctions pursuant to 35 U.S.C. § 285, as
well as under Federal Rules of Civil Procedure 54(d) and
37(c)(2). The district court granted the request for fees and
costs, and based its exceptional case finding on O2 Micro’s
“vexatious litigation strategy, litigation misconduct and
unprofessional behavior.” Exceptional Case Order, at *21.
It found O2 Micro to have employed, “on multiple occasions,”
a vexatious litigation strategy in which O2 Micro “sued MPS
customers, prompting MPS to file declaratory judgment
actions.” Id. at *16. Thereafter, O2 Micro would “covenant[]
not to sue, thereby enabling it to avoid litigation on the
validity of its patents.” Id. The district court emphasized
8                MONOLITHIC POWER SYSTEMS, INC.     v. O2 MICRO
                                           INTERNATIONAL LTD.


that O2 Micro withdrew and dismissed its claims only after
“substantial litigation had taken place,” and, in this case,
“only after MPS and ASUSTeK completed their filings for
the parties’ impending final pretrial conference”—causing a
waste of substantial resources.
     The district court also detailed O2 Micro’s litigation mis-
conduct and unprofessional behavior. It recounted the
extent to which O2 Micro’s various misrepresentations
concerning how Dr. Lin’s schematics came to be dated
“Feb., 18, 1998” affected the proceedings, from discovery
through summary judgment. It enumerated at least three
“baseless motions” O2 Micro had filed concerning the sche-
matics issue, needlessly prolonging the litigation. Id. at
*19–20. It explained that instead of “straightforwardly
admitting the truth,” O2 Micro “dissembled and sought,
through motion practice, to mask its proffer of false testimo-
ny.” Id. at *20. Taken together with O2 Micro’s vexatious
litigation strategy, the district court found that O2 Micro’s
course of conduct rises to the level of being “exceptional.”
     Based on these findings, the district court decided that
MPS and ASUSTeK were entitled to attorney fees, but
reserved its decision on the amount of fees pending further
briefing and documentation. Id. at *21. The district court
reviewed the clerk’s taxation of costs, allowing some and
disallowing others, and calculated the amount of $339,315 to
be taxed against O2 Micro. Id. at *22–30. The court also
reasoned, over O2 Micro’s broad objection, that expenses
incurred in the ITC investigation were recoverable even
though they did not arise in the district court action. Specif-
ically, O2 Micro had been on notice that discovery taken in
the ITC investigation was deemed to apply to this action;
indeed, O2 Micro never objected and even used the discovery
obtained. O2 Micro also acknowledged the significant
overlap of issues and patents between this action and the
ITC investigation. And, finally, had O2 Micro not precipi-
MONOLITHIC POWER SYSTEMS, INC.    v. O2 MICRO               9
INTERNATIONAL LTD.


tated the ITC investigation, the same discovery-related costs
would have been incurred in this litigation. Id. at *23–24.
    Thereafter, the parties submitted the requested briefing
and documentation on attorney fees, nontaxable costs, and
expert witness fees. In its briefing objecting to attorney fees
and costs, O2 Micro argued that there should be a close
nexus between the misconduct found and the fees awarded.
O2 Micro also repeated its previous argument that expenses
incurred in the ITC investigation should not be recoverable.
On January 17, 2012, the district court awarded $663,151 in
nontaxable costs against O2 Micro, denied the request for
expert witness fees, and further ordered MPS and ASUSTeK
to submit a revised calculation of the requested fees in
accordance with its discussion of what is and is not allowa-
ble. Fees and Costs Order, at *11–20. In response to O2
Micro’s “nexus” argument, the district court referenced its
Exceptional Case Order in concluding that O2 Micro’s mis-
conduct had been so “pervasive throughout the entire case”
that “an award of fees for the entire case is appropriate.”
Fees and Costs Order, at *15. As for O2 Micro’s general
objection to fees and costs incurred in the ITC investigation,
the district court had previously found them to be recovera-
ble given their dual use purpose under the circumstances.
Exceptional Case Order, at *23–24.
    On May 3, 2012, after scrutinizing the parties’ last
round of submissions, the district court awarded $8,419,429
in attorney fees and entered judgment against O2 Micro.
Monolithic Power Sys., Inc. v. O2 Micro Int’l Ltd., No. 08-
4567, 2012 U.S. Dist. LEXIS 62230 (N.D. Cal. May 3, 2012)
(“Final Order on Fees”).
    O2 Micro timely appealed from that judgment. We have
jurisdiction pursuant to 28 U.S.C. § 1295(a)(1).
10               MONOLITHIC POWER SYSTEMS, INC.    v. O2 MICRO
                                          INTERNATIONAL LTD.


                         DISCUSSION
     O2 Micro argues that the district court: (1) applied the
wrong standard in declaring this case exceptional under
35 U.S.C. § 285; (2) clearly erred in finding the case to be
exceptional; and (3) abused its discretion in awarding attor-
ney fees that were not traceable to or caused by O2 Micro’s
litigation misconduct. We address each argument in turn.
     We review de novo whether the district court applied the
correct legal standard under § 285. Forest Labs., Inc. v.
Abbot Labs., 339 F.3d 1324, 1328 (Fed. Cir. 2003). We
review a district court’s factual determinations underlying
an exceptional case finding for clear error. Id. The decision
to award attorney fees, as well as the amount of fees, is
reviewed under an abuse of discretion standard. Molins
PLC v. Textron, Inc., 48 F.3d 1172, 1186 (Fed. Cir. 1995); see
Beckman Instruments, Inc. v. LBK Produkter AB, 892 F.2d
1547, 1553 (Fed. Cir. 1989) (“The determination of the
amount of the award remains within the discretion of the
trial court, since it is the trial judge who is in the best
position to know how severely [a party’s] misconduct has
affected the litigation.”).
               A. Exceptional Case Standard
    O2 Micro asserts that the district court applied the
wrong legal standard in declaring the case exceptional. It
faults the district court for failing to make findings concern-
ing O2 Micro’s “bad faith” in bringing an “objectively base-
less” litigation, which it argues is required by Professional
Real Estate Investors, Inc. v. Columbia Pictures Industries,
Inc., 508 U.S. 49 (1993). Citing Brooks Furniture Manufac-
turing, Inc. v. Dutailier International, Inc., O2 Micro con-
tends that sanctions under § 285 may be imposed only when
there is evidence that the losing party brought the objective-
ly baseless litigation in bad faith. 393 F.3d 1378, 1381 (Fed.
Cir. 2005).
MONOLITHIC POWER SYSTEMS, INC.    v. O2 MICRO              11
INTERNATIONAL LTD.


     We have observed that, as a general matter, many forms
of misconduct can support a district court’s exceptional case
finding, including inequitable conduct before the U.S. Patent
and Trademark Office (“PTO”); litigation misconduct; vexa-
tious, unjustified, and otherwise bad faith litigation; a
frivolous suit; or willful infringement. Brasseler, U.S.A. I,
L.P. v. Stryker Sales Corp., 267 F.3d 1370, 1380 (Fed. Cir.
2001) (citing Hoffmann-La Roche Inc. v. Invamed Inc., 213
F.3d 1359, 1365 (Fed. Cir. 2000)). And, as we made clear in
Rambus Inc. v. Infineon Technologies AG, “[l]itigation
misconduct and unprofessional behavior may suffice, by
themselves, to make a case exceptional under § 285.” 318
F.3d 1081, 1106 (Fed. Cir. 2004). Indeed, it is only absent
litigation misconduct or misconduct in securing the patent
that we require the finding of both “bad faith” and “objec-
tively baseless” litigation to warrant sanctions under § 285.
Brooks Furniture, 393 F.3d at 1381. In other words, litiga-
tion misconduct alone may suffice to make a case exception-
al.
      In its opinion, the district court cited Brooks Furniture
for the exceptional case standard: “A case may be deemed
exceptional when there has been some material inappropri-
ate conduct related to the matter in litigation, such as . . .
misconduct during litigation, vexatious or unjustified litiga-
tion, conduct that violates FED. R. CIV. P. 11, or like infrac-
tions.” Exceptional Case Order, at *15. Moreover, before
discussing the various instances of O2 Micro’s misconduct,
the district court also cited Taltech Ltd. v. Esquel Enterpris-
es Ltd., 604 F.3d 1324, 1329 (Fed. Cir. 2010), to clarify that
“[l]itigation misconduct and unprofessional behavior are
relevant to the award of attorney fees, and may suffice to
make a case exceptional.” Exceptional Case Order, at *18.
     Thus, O2 Micro is incorrect in suggesting that findings
of “bad faith” and “objectively baseless” litigation are always
required in addition to a “litigation misconduct” finding for
12               MONOLITHIC POWER SYSTEMS, INC.     v. O2 MICRO
                                           INTERNATIONAL LTD.


an exceptional case. The district court applied the correct
standard. It also correctly explained that, having found O2
Micro’s litigation misconduct sufficient to render the case
exceptional, it need not also consider whether O2 Micro
committed inequitable acts before the PTO or filed an
objectively baseless litigation.
                B. Exceptional Case Finding
     O2 Micro also argues that the district court clearly erred
in making the exceptional case determination because both
of its findings—“vexatious litigation strategy” and “litigation
misconduct”—are unsupported in fact. O2 Micro asserts
that its defeat of summary judgment of noninfringement
constitutes evidence sufficient to overcome any argument
that its assertion of infringement was objectively baseless or
made in bad faith. It also maintains that its “good faith
mistake about how the schematics came to be dated,” Appel-
lant’s Br. 33–34, its “prompt acknowledgement of its mis-
take,” and the “corrective measures” it took upon making
that discovery, id. at 38, do not amount to litigation miscon-
duct. In the interest of streamlining the case with respect to
establishing the invention date of the ’382 patent, O2 Micro
argues that it had reasonable bases for filing summary
adjudication motions and an evidentiary motion to strike.
Finally, O2 Micro disputes that its litigation strategy was
vexatious or that the purpose of its lawsuit was improper.
     O2 Micro’s arguments are meritless. First, O2 Micro
fails to appreciate the “well-established [rule] that litigation
misconduct and unprofessional behavior may suffice, by
themselves, to make a case exceptional under § 285.”
MarcTec, LLC v. Johnson & Johnson, 664 F.3d 907, 919
(Fed. Cir. 2012) (internal quotation marks omitted). In-
stead, O2 Micro’s arguments challenging the exceptional
case determination hinge on its mistaken conviction that
there must be an additional “bad faith” component to litiga-
tion misconduct or that vexatiousness may be found only
MONOLITHIC POWER SYSTEMS, INC.     v. O2 MICRO                13
INTERNATIONAL LTD.


when coupled with the assertion of “objectively baseless”
positions. Additional components are simply not required
for an exceptional case finding based on litigation miscon-
duct.
     Second, the district court’s findings of an overall vexa-
tious litigation strategy and numerous instances of litigation
misconduct are sufficient to support an exceptional case
determination. The record provides ample grounds for the
district court to find that O2 Micro had undertaken a vexa-
tious litigation strategy. Having presided over a decade of
litigation between O2 Micro and MPS, the district court
witnessed several instances in which O2 Micro sued MPS
customers in order to prompt MPS to file declaratory judg-
ment actions with the court. In each previous case, O2
Micro withdrew its claims and granted covenants not to sue
after substantial litigation had taken place. In the underly-
ing case, O2 Micro employed its modus operandi, this time
moving to dismiss only after MPS and ASUSTeK had com-
pleted their filings for the final pretrial conference, wasting
the parties’ and the court’s resources. The district court,
with its unparalleled familiarity with and insight into O2
Micro’s motivations and repeated resort to these tactics,
assessed that this pattern amounted to a vexatious litigation
strategy that would support a finding of exceptional case.
We decline to disturb that assessment.
    Similarly, the district court’s recount of the series of “lit-
igation misconduct and unprofessional behavior” by O2
Micro is well-grounded and supports the finding of an
exceptional case. O2 Micro repeatedly misrepresented that
the date of the schematics was computer-generated and not
manually entered, having three witnesses testifying to the
same. O2 Micro failed to conduct an investigation into the
veracity of its representations until after MPS had retained
a schematics expert to debunk its version of events. After
the exposure, O2 Micro supplemented its verified interroga-
14               MONOLITHIC POWER SYSTEMS, INC.    v. O2 MICRO
                                          INTERNATIONAL LTD.


tory regarding the date of the schematics with a “convoluted
paragraph in which it obfuscated the fact that Lin had
entered the date.” Exceptional Case Order, at *19. Thereaf-
ter, O2 Micro filed three “baseless motions”—a motion to
strike MPS’s expert report and expert testimony on the
schematics and two motions for summary adjudication to
foreclose further litigation as to the authenticity of the
schematics and the conception date of the subject matter
claimed in the ’382 patent—to bury the past. As the district
court found, “[r]ather than straightforwardly admit the
truth, O2 Micro dissembled and sought, through motion
practice, to mask its proffer of false testimony.” Id. at *20.
Considering the totality of the circumstances, the district
court then concluded that this series of misconduct, along
with O2 Micro’s overall vexatious litigation strategy, war-
ranted designating the case exceptional. See Yamanouchi
Pharm. Co. v. Danbury Pharmacal, Inc., 231 F.3d 1339,
1347 (Fed. Cir. 2000) (“In assessing whether a case qualifies
as exceptional, the district court must look at the totality of
the circumstances.”).
    Having reviewed the district court’s findings as well as
the record on appeal, we are well satisfied with the district
court’s conclusion that misconduct and unprofessional
behavior occurred. We are certainly not left with the convic-
tion that the district court committed clear error in finding
the case exceptional. In any event, it “ill behooves an appel-
late court to overrule a trial judge concerning litigation
misconduct when the litigation occurred in front of the trial
judge, not the appellate court.” Nilssen v. Osram Sylvania,
Inc., 528 F.3d 1352, 1359 (Fed. Cir. 2008).
                  C. Attorney Fees Award
    As noted above, the bulk of the $8,419,429 attorney fees
award was for discovery-related expenses incurred in the
ITC investigation. The district court allowed recovery for
these expenses based on the parties’ agreement to take
MONOLITHIC POWER SYSTEMS, INC.    v. O2 MICRO              15
INTERNATIONAL LTD.


discovery for “dual use” in the parallel ITC and district court
proceedings. See Exceptional Case Order, at *23–24.
     O2 Micro argues that it was an abuse of discretion for
the district court to award fees that are not traceable solely
to O2 Micro’s “exceptional” behavior in the litigation. O2
Micro relies on Fox v. Vice, 131 S. Ct. 2205 (2011), to support
its contention that an award of attorney fees must be limited
to those fees that would not have been incurred “but for” its
acts of misconduct. See id. at 2215. Although O2 Micro
concedes that discovery taken in the ITC proceeding was
used by the parties in the district court case, it argues that
these fees do not satisfy the “but for” test because they
would have been incurred even if the district court case had
not been filed.
     According to O2 Micro, the ITC-related fees 3 are espe-
cially problematic because, unlike district courts, the ITC
imposes no limits on discovery. O2 Micro also relies on
Highmark, Inc. v. Allcare Health Management Systems for
its position that where there is a fee award based on litiga-
tion misconduct, the amount should be that which is neces-
sary to compensate a party for the “extra legal effort to
counteract” the misconduct. 687 F.3d 1300, 1316 (Fed. Cir.
2012). O2 Micro explains that because the district court had
not found its actions in the ITC investigation to constitute
misconduct, fees incurred in investigation should not be part
of the award.

    3   To clarify, the fee award does not include fees for
work related solely to the ITC proceeding, such as ex-
penses incurred in connection with efforts to prove the
existence of a domestic industry. The only ITC-related
fees that were awarded were for expenses relating to
discovery, which the parties agreed would be taken for
“dual use” in both the ITC and the district court proceed-
ings.
16              MONOLITHIC POWER SYSTEMS, INC.    v. O2 MICRO
                                         INTERNATIONAL LTD.


    MPS and ASUSTeK contend that O2 Micro has waived
the “but for” argument on appeal by failing to raise it below.
The appellees acknowledge that O2 Micro objected to the
recovery of any fees related to the ITC investigation in the
proceedings below, but assert that the objection did not
encompass its current “but for” theory. MPS and ASUSTeK
also argue that even if O2 Micro’s “but for” argument is not
waived, Fox is inapposite to this case because its application
is limited to civil rights suits, brought under
42 U.S.C. § 1988(b), that involve both frivolous and nonfrivo-
lous claims. Lastly, MPS and ASUSTeK assert that the
district court’s finding that O2 Micro’s misconduct was
“pervasive throughout the entire case” justified its discre-
tionary award of fees for the entire case.
    At the outset, we find that O2 Micro has not waived its
“but for” argument. O2 Micro had previously urged the
same argument in its papers filed in opposition to the mo-
tion for fees. Moreover, O2 Micro had submitted the Fox
opinion to the district court in a notice of supplemental
authority that was filed after the attorney fees briefing was
complete but before the district court ruled on the matter.
Indeed, the district court, in the Fees and Costs Order,
addressed—and rejected—O2 Micro’s “but for” argument, at
*13–15, and had found Fox to be inapplicable to a case that
did not contain a frivolous claim, at *15 n.4. We would be
hard pressed to find a waiver in these circumstances.
    On the merits, we find that Fox is not applicable to this
case. The issue in Fox was the allocation of fees between
frivolous and nonfrivolous claims in a single lawsuit. See
Fox, 131 S. Ct. at 2211. In contrast, the situation here
concerns the allocation of fees incurred in separate, but
parallel, proceedings—neither of which involved a frivolous
claim. O2 Micro is, however, correct to point out the obser-
vation in Highmark that an exceptional case finding based
on litigation misconduct “usually does not support a full
MONOLITHIC POWER SYSTEMS, INC.   v. O2 MICRO              17
INTERNATIONAL LTD.


award of attorney’s fees.” Highmark, 687 F.3d at 1316
(citing Beckman Instruments, 892 F.2d at 1553). Instead, a
fee award “must bear some relation to the extent of the
misconduct, and compensate a party for the extra legal effort
to counteract the misconduct.” Id. (citations omitted) (inter-
nal quotation marks omitted).
     However, as evident in the district court’s Exceptional
Case Order and in the record before us, this case was any-
thing but usual and the extent of O2 Micro’s misconduct was
anything but limited. Indeed, the litigation misconduct
finding by the district court was not of isolated instances of
unprofessional behavior by O2 Micro. Rather, O2 Micro’s
extensive misconduct was enough to comprise an abusive
“pattern” or a vexatious “strategy” that was “pervasive”
enough to infect the entire litigation. Exceptional Case
Order, at *16–21; Fees and Costs Order, at *15. The district
court found that O2 Micro’s “exceptional” conduct began
before it was even served with MPS’s complaint, when it
filed a complaint in the ITC against MPS and MPS’s cus-
tomers in retaliation for the declaratory judgment action
MPS had filed against it. O2 Micro’s antics surrounding the
date of the schematics also took on many forms throughout
the litigation, affecting several rounds of written discovery,
deposition testimony, and baseless motions including at the
summary judgment stage. Finally, O2 Micro employed its
usual tactic of granting covenants not to sue only after
substantial work had been completed in this case.
    Based on the examples of unprofessional behavior pro-
vided by the district court and the many more instances of it
we were able to glean from the record, we agree with the
district court that O2 Micro’s rampant misconduct so severe-
ly affected every stage of the litigation that a full award of
attorney fees was proper here. Under the unique circum-
stances, the district court’s award of ITC-related expenses is
also not an abuse of discretion, especially in view of the
18               MONOLITHIC POWER SYSTEMS, INC.    v. O2 MICRO
                                          INTERNATIONAL LTD.


discovery’s application in the district court and the parties’
agreement to its dual use.
    Further, we note that the district court clarified that the
award discounted by ten percent all attorney fees incurred
and included only twenty-five percent of the requested fees
from block-billed time entries, resulting in a significant
reduction in the amount. Final Order on Fees, at *3–4. This
demonstrates to us a careful exercise of discretion by the
district court, and not an abuse of it.
    More than a decade ago, the Beckman Instruments court
foretold, “we can certainly imagine a case in which litigation
misconduct would justify an award of attorney fees for the
entire litigation.” Beckman Instruments, 892 F.2d at 1553.
We are quite confident that this was the kind of case it had
in mind.
                         CONCLUSION
    O2 Micro has not persuaded us that the district court’s
exceptional case finding was clearly erroneous. We also
detect no abuse of discretion by the district court in award-
ing attorney fees. Accordingly, the judgment of the district
court is affirmed.
                        AFFIRMED
