United States Court of Appeals 

for the Federal Circuit ______________________ 

TRADING TECHNOLOGIES INTERNATIONAL, 

INC.,

Plaintiff-Appellant,

 v.

 OPEN E CRY, LLC, AND OPTIONSXPRESS 

HOLDINGS, INC.,

Defendants-Appellees, 

AND

 TRADESTATION SECURITIES, INC., AND

TRADESTATION GROUP, INC., 

Defendants-Appellees, 

AND 

 IBG, LLC, THINKORSWIM GROUP, INC., 

TD AMERITRADE, INC., TD AMERITRADE 

HOLDING CORP., AND INTERACTIVE BROKERS, 

LLC, 

Defendants-Appellees, 

AND 

 CQG, INC., AND CQGT, LLC, 

Defendants-Appellees, 

AND 
2 TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC

FUTUREPATH TRADING LLC, 

SUNGARD DATA SYSTEMS, INC., 

 SUNGARD INVESTMENT VENTURES LLC, AND 

GL TRADE AMERICAS, INC., 

Defendants-Appellees, 

AND 

STELLAR TRADING SYSTEMS, LTD., AND

STELLAR TRADING SYSTEMS, INC., 

Defendants-Appellees, 

AND 

ESPEED MARKETS, LP, 

BGC CAPITAL MARKETS, LP, AND 

ECCOWARE LTD., 

Defendants-Appellees, 

AND 

ROSENTHAL COLLINS GROUP, LLC,

Defendant.

______________________ 

2012-1583 

______________________ 

Appeal from the United States District Court for the 

Northern District of Illinois in consolidated No. 10-CV0715, Judge Virginia M. Kendall. 

______________________ 

Decided: August 30, 2013 

______________________ 
TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC 3

STEVEN F. BORSAND, Trading Technologies International, Inc., of Chicago, Illinois, argued for plaintiffappellant. Of counsel on the brief were LEIF R. SIGMOND,

JR., MICHAEL D. GANNON, PAUL A. KAFADAR, and SARAH E.

FENDRICK, McDonnell Boehnen Hulbert & Berghoff LLP, 

of Chicago, Illinois. Of counsel were JENNIFER KURCZ and 

MATTHEW SAMPSON. 

ANTHONY B. ULLMAN, Salans LLP, of New York, New 

York, argued for all defendants-appellees. With him on 

the brief for FuturePath Trading, LLC, et al., was LORA A.

MOFFATT. Of counsel on the brief were PHILIPPE BENNETT

and AOIFE BUTLER, Alston & Bird, LLP, of New York, 

New York. On the brief for IBG, LLC, et al., were 

MICHAEL BRETT LEVIN and CHRISTOPHER P. GREWE, 

Wilson Sonsini Goodrich & Rosati, of Palo Alto, California, and NATALIE J. MORGAN, of San Diego, California. 

On the brief for CQG, Inc., et al., were ADAM G. KELLY,

WILLIAM J. VOLLER, and J. SIMONE JONES, Loeb & Loeb, 

LLP, of Chicago, Illinois. On the brief for eSpeed Markets, LP, et al., was GARY A. ROSEN, Law Offices of Gary 

A. Rosen, P.C., of Ardmore, Pennsylvania. On the brief 

for TradeStation Securities, Inc., et al., were DAVID J.

HEALEY, Fish & Richardson P.C., of Houston, Texas, and 

ADAM KESSEL and KEVIN SU, of Boston, Massachusetts. 

SCOTT J. BORNSTEIN, Greenberg Traurig, LLP, of New 

York, New York, for defendants-appellees Open E. Cry, 

LLC, et al. With him on the brief was JAMES J. LUKAS,

JR., of Chicago, Illinois. 

LAURA A. LYDIGSEN, Brinks Hofer Gilson & Lione, of 

Chicago, Illinois, for defendants-appellees, Stellar Trading Systems, Ltd., et al. Of counsel were RALPH J. GABRIC

and MARC V. RICHARDS. 

______________________ 
4 TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC

Before LOURIE and PLAGER, Circuit Judges, and BENSON,

District Judge.*

 

* Honorable Dee V. Benson, District Judge, United 

States District Court for the District of Utah, sitting by 

designation. 

LOURIE, Circuit Judge. 

 In this patent infringement action, Plaintiff-Appellant 

Trading Technologies International, Inc. (“TT”) appeals 

from the district court’s entry of summary judgment that 

(i) the asserted claims of TT’s U.S. Patents 7,676,411 (the 

“’411 patent”), 7,693,768 (the “’768 patent”), 7,904,374 

(the “’374 patent”), and 7,685,055 (the “’055 patent”) are 

invalid for failure to comply with the written description 

requirement of 35 U.S.C. § 112; and (ii) prosecution 

history estoppel bars TT from asserting the ’055 patent 

against software products that include certain display 

functions. The district court premised both holdings on 

deference to our prior decision in Trading Technologies 

International, Inc. v. eSpeed, Inc., 595 F.3d 1340 (Fed. 

Cir. 2010) (“eSpeed”), which considered two related patents from TT’s portfolio. 

We conclude that eSpeed does not control the issues 

presented in this appeal, and the district court’s rulings 

based on that case are therefore incorrect. Accordingly, 

and as described more fully below, we reverse and remand 

for further proceedings. 

BACKGROUND

A. The TT Patent Family 

TT owns a number of related patents generally directed to software used for electronic trading on a commodities exchange, including the ’411, ’768, ’374, and ’055 

patents at issue in this appeal. Issued between March 

2010 and March 2011, those four patents claim priority 
TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC 5

from U.S. Provisional Patent Application 60/186,322, filed 

on March 2, 2000, and U.S. Patent Application 

09/590,692, which was filed on June 9, 2000, and later 

issued as U.S. Patent 6,772,132 (the “’132 patent”) on 

August 3, 2004. The ’411, ’768, and ’374 patents all arose 

from a series of continuation applications stemming from 

the parent ’132 patent. See, e.g., ’411 patent, at [63]. 

Accordingly, the ’411, ’768, and ’374 patents share a 

common written description matching that of the progenitor ’132 patent in all material respects. In contrast, the 

’055 patent traces its priority from the ’132 patent as a 

continuation-in-part, see ’055 patent, at [63], and as such, 

the ’055 patent contains substantial new matter relative 

to the original written description of the ’132 patent. 

In general, the subject TT patents concern a graphical 

user interface that can display essential data from a 

commodities market and allow a user to enter electronic 

trade orders on an exchange. Drawings common to the 

’411, ’768, ’374, and ’055 patents exemplify several key 

aspects of the disclosed displays: 

 
6 TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC

E.g., ’411 patent, figs. 3, 4. Figure 3 depicts a trading 

display that conveys up-to-date market information, 

including the pending bids and offers at various price 

points. Column 1005, labeled “Prc,” represents various 

contract prices for the commodity of interest. Id. col. 7 

ll. 55–58. Adjacent to the price column are bid and ask 

columns 1003 and 1004, labeled “BidQ” and “AskQ,” 

respectively. Those columns show the current bid quantities (offers to buy) and ask quantities (offers to sell) at 

each price, id. col. 7 ll. 54–55, and a trader can enter new 

trade orders by clicking on the bid and ask columns, id.

col. 10 ll. 19–23. The “inside market,” labeled 1020, spans 

the highest current bid price and the lowest current ask 

price. Id. col. 4 ll. 60–62. In general, the inside market 

approximates the commodity’s market price and therefore 

marks a focus of trading activity. In figure 3, the inside 

market includes a highest bid price of 89 and a lowest ask 

price of 90. 

Figure 4 shows the same display, with data for the 

same market, viewed at a later point in time. ’411 patent 

col. 3 ll. 47–48. Over time, the inside market can “ascend 

and descend as prices in the market increase and decrease.” Id. col. 9 ll. 4–5. As illustration, the inside 

market in figure 4, labeled 1101, has shifted up the price 

column to 92/93 from its earlier range of 89/90 in response 

to intervening trades. 

 According to the patents, traders able to view and 

quickly appreciate such detailed market data can more 

readily identify (and capitalize upon) developing trends in 

an active market. Id. col. 6 ll. 12–30. To that end, the 

disclosed graphical user interfaces offer a logical and 

intuitive means to convey dynamic market information 

using bid, ask, and inside market indicators that visually 

track ongoing price fluctuations along the price column. 

Moreover, the patents combine a market grid, a summary 

of market orders, and an order entry system into a single 

display. In short, “[s]uch a condensed display materially 
TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC 7

simplifies the trading system by entering and tracking 

trades in an extremely efficient manner.” Id. col. 7 ll. 40–

42. 

 Nonetheless, allowing the inside market to move up 

and down the display presents a problem: “As the market 

ascends or descends the price column, the inside market 

might go above or below the price column displayed on a 

trader’s screen.” Id. col. 9 ll. 15–17. Because the inside 

market informs most trading decisions, the display must 

provide a way to re-center the price column and bring the 

inside market back into view. The parent ’132 written 

description shared by the ’411, ’768, and ’374 patents 

explains that the values in the price column “are static; 

that is, they do not normally change positions unless a recentering command is received,” id. col. 7 ll. 64–66, and 

further describes a “one click” centering feature that 

allows a user to re-center the price column around the 

inside market with a single mouse click, id. col. 9 ll. 17–

25. 

B. The eSpeed Decision 

 As noted, this appeal is not the first to reach this 

court concerning TT’s trading software patents. In 

eSpeed, we considered, inter alia, the correct construction 

of certain claim terms used in the ’132 patent and in 

another of its many descendants, U.S. Patent 6,766,304 

(the “’304 patent”). The ’304 patent, like the ’411, ’768, 

and ’374 patents, shares the written description of the 

parent ’132 patent.1

 In eSpeed, TT had asserted claims from the ’132 and 

’304 patents against several providers of electronic trading software. 595 F.3d at 1347–48. Each of the asserted 

 1 The ’304 patent issued from a division of the 

application underlying the ’132 patent. ’304 patent, at 

[62]. 
8 TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC

claims required a graphical user interface having a “static” display of market price information,2 and the district 

court had construed that term to require “a display of 

prices comprising price levels that do not change positions 

unless a manual re-centering command is received.” Id.

at 1352. On appeal, TT argued that a “static” price column could work with non-manual modes of re-centering. 

Id. at 1353. 

 Relying on the ’132 and ’304 patents’ shared written 

description, the surrounding claim language, and the 

relevant prosecution history, we adopted the district 

court’s construction. See id. at 1353–55. In particular, we 

concluded that “[t]he inventors’ own specification strongly 

suggests that the claimed re-centering feature is manual” 

because the written description “only discusse[d] manual 

re-centering commands” and referred to “the present 

invention” as including a manual one-click re-centering 

feature. Id. at 1353–54. Consistent with that view, we 

also noted that the claims of the ’132 patent recited an 

additional limitation stating that the “static” price display 

would not move in response to changes in the inside 

market, expressly excluding displays that re-center automatically when the inside market shifts. Id. at 1354. 

Finally, we highlighted statements made by the applicants during prosecution. Specifically, the examiner had 

first considered the term “static display” to be indefinite, 

but the applicants responded by explaining that the 

values in the price column would not change absent a re-

 2 The asserted claims of the ’132 patent required a 

“static display of prices,” while the asserted claims of the 

’304 patent required a “common static price axis.” The 

eSpeed claim construction debate nonetheless turned on 

the meaning of “static” because all agreed that “the 

difference in terminology between ‘static display of prices’ 

and ‘common static price axis’ [was] immaterial.” eSpeed, 

595 F.3d at 1352. 
TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC 9

centering command, and the claims were then allowed on 

that basis. Id. at 1354. Accordingly, the full record before 

us in eSpeed led us to conclude that the proper construction of “static,” as used in the claims of the ’132 and ’304 

patents, required a price column that moves only in 

response to a manual re-centering command. 

 In addition, we rejected TT’s attempts to invoke the 

doctrine of equivalents to find that products practicing 

automatic re-centering nonetheless infringed its claims to 

“static” displays. See id. at 1355–57. We held that prosecution history estoppel precluded such infringement 

theories because the applicants had amended the claims 

of the ’132 and ’304 patents to make clear that the 

claimed “static” price levels did not move in response to 

changes in the inside market, thus “surrender[ing] any 

subject matter that moves automatically.” Id. at 1357. 

Thus, in eSpeed, “both claim construction and prosecution 

history estoppel operate[d] . . . with similar limited results.” Id.

C. Prosecution of the ’411, ’768, ’374, and ’055 Patents 

 While the eSpeed litigation progressed through the 

courts, four patent applications that eventually became 

the ’411, ’768, ’374, and ’055 patents were filed in the 

United States Patent and Trademark Office. TT followed 

two distinct approaches to prosecuting those applications 

in view of eSpeed. Those approaches are key to the resolution of this appeal. 

1. The ’411, ’768, and ’374 Continuations 

With the applications for the ’411, ’768, and ’374 patents—three parallel continuations that relied on the 

original written description of the ’132 patent—TT sought 

claims that removed the term “static” from references to 

the price column. For example, following the district 

court’s adverse claim construction determinations in the 
10 TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC

eSpeed litigation,3 TT amended the application for the 

’411 patent. Up to that time, the application had claimed 

methods requiring “statically” displayed market price 

information, similar to the claims of the related ’132 and 

’304 patents at issue in eSpeed. But TT’s amendment 

cancelled every pending claim and introduced new claims 

that lacked the term “static” in any form, and that term 

remained absent from the claims issued in the ’411 patent. In addition, TT made comparable amendments to 

the co-pending applications that gave rise to the ’768 and 

’374 patents. 

Therefore, while the written descriptions of the ’411, 

’768, and ’374 patents match those of the earlier ’132 and 

’304 patents, the claims differ between the two groups in 

at least one key respect—unlike the ’132 and ’304 patents 

at issue in eSpeed, the ’411, ’768, and ’374 patents claim 

trading methods and software without limitation to a 

“static” price column display. 

2. The ’055 Continuation-in-Part 

TT pursued a different strategy with the application 

for the ’055 patent. That application claimed priority 

from the ’132 patent as a continuation-in-part, which 

allowed TT to add new disclosures to the parent’s written 

description. In part, those additional disclosures were 

aimed at redefining the term “static” as used in the ’055 

patent: 

 3 In that case, the district court issued an initial 

claim construction ruling on October 31, 2006, and then 

issued another order clarifying its original construction on 

February 21, 2007. Trading Techs. Int’l, Inc. v. eSpeed, 

Inc., Nos. 04-c-5312, 05-c-1079, 05-c-4088, 05-c-4120, 05-c4811, 05-c-5164, 2006 WL 3147697 (N.D. Ill. Oct. 31, 

2006), clarified, 2007 WL 611258 (N.D. Ill. Feb. 21, 2007). 
TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC 11

Certain of the trading tools work particularly well 

with a trading display that shows working orders . 

. . displayed in association with a static price scale 

or axis. . . . It is to be understood that, in this context, static does not mean immovable, but rather 

means fixed in relation. For example, with a static price scale, the scale itself may be movable, but 

the prices represented remain fixed in relation to 

each other . . . . 

’055 patent col. 4 ll. 48–57 (emphases added); see also id.

col. 25 ll. 4–12 (“In one embodiment, the trading application tracks the market’s activity by automatically centering, for example, the inside market . . . on the display 

with respect to a static axis or scale of prices.”); id. col. 26 

ll. 30–37 (“A trader may use automatic positioning to 

always have a visual reference of where the market is 

trading . . . . In addition, automatic positioning may be 

used in conjunction with manual positioning.”). 

 The claims of the ’055 patent likewise recite steps that 

include displaying “a static price axis” and “automatically 

repositioning the static price axis on the graphical user 

interface.” Id. col. 34 ll. 15–67. By their terms, the claims 

of the ’055 patent thus require a “static price axis” capable 

of re-centering via automatic rather than manual commands. 

D. District Court Proceedings 

 In early 2010, TT filed twelve separate infringement 

actions targeting numerous defendants, including: Open 

E Cry, LLC; optionsXpress Holdings, Inc.; TradeStation 

Securities, Inc.; TradeStation Group, Inc.; IBG, LLC; 

thinkorswim Group, Inc.; TD Ameritrade, Inc.; TD Ameritrade Holding Corp.; Interactive Brokers, LLC; CQG, Inc.; 

CQGT, LLC; FuturePath Trading, LLC; SunGard Data 

Systems, Inc.; SunGard Investment Ventures LLC; GL 

Trade Americas, Inc.; Stellar Trading Systems, Ltd.; 

Stellar Trading Systems, Inc.; eSpeed Markets, LP; BGC 
12 TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC

Capital Markets, LP; Eccoware, Ltd.; and Rosenthal 

Collins Group, LLC (collectively, “Defendants”).4 Through 

a series of supplements and amendments to the original 

complaints, TT variously accused the Defendants of 

infringing claims from more than ten patents relating to 

electronic trading software, of which only the ’411, ’768, 

’374, and ’055 patents are before us in this appeal. The 

district court consolidated the cases on February 3, 2011. 

Trading Techs. Int’l, Inc. v. BGC Partners, Inc., No. 10-cv715 (N.D. Ill. Feb. 3, 2011), ECF No. 70 (Consolidation 

Order). 

 After consolidation, the parties submitted opposing 

summary judgment motions on several issues, including 

whether the claims of the ’411 patent satisfied the written 

description requirement of 35 U.S.C. § 112(a) in light of 

eSpeed and whether prosecution history estoppel barred 

TT from asserting infringement under the doctrine of 

equivalents as to products with price columns that move 

automatically. Trading Techs. Int’l, Inc. v. BCG Partners, 

Inc., 852 F. Supp. 2d 1027, 1029–30 (N.D. Ill. 2012) 

(“Summary Judgment Order”). 

 First, the district court concluded that eSpeed required holding the claims of the ’411 patent invalid for 

lack of written description. The court acknowledged that 

eSpeed did not involve the ’411 patent or the written 

description requirement and instead dealt primarily with 

construing the term “static” in the claims of the ’132 and 

’304 patents. Id. at 1044. Nevertheless, the district court 

reasoned that eSpeed “made a number of findings regarding the specification in the course of affirming the claim 

construction that are dispositive here.” Id. 

 4 Although a defendant before the district court, 

Rosenthal Collins Group, LLC is not a party to this 

appeal. 
TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC 13

According to the district court, eSpeed’s construction 

of “static” in the ’132 and ’304 patents turned “on the 

premise that the invention described in the specification 

was limited to static price axes that move only with 

manual re-centering.” Id. at 1045. Because the ’411 

patent’s claims lacked that term and therefore appeared 

to cover displays with automatic re-centering, the district 

court concluded that any decision upholding those broader 

claims as supported by the same written description 

“would be at odds with the Federal Circuit’s binding 

findings in the eSpeed Decision.” Id. In granting the 

Defendants’ motion for summary judgment, the district 

court expressly declined to evaluate the parties’ evidence 

or make its own findings on the merits because the court 

determined “as a matter of law that the eSpeed Decision 

controls.” Id. at 1038 n.9; see also id. at 1045 n.13. 

In addition, the district court held that eSpeed’s application of prosecution history estoppel to the ’132 and ’304 

patents applied equally to the ’055 patent as a matter of 

law.5 The court noted that the ’055 patent’s claims “include the limitation of ‘common static price axis,’ just like 

the ’304 patent, and flow from . . . a similar specification.” 

Summary Judgment Order, 852 F. Supp. 2d at 1046–47. 

The court then concluded that when “‘multiple patents 

derive from the same initial application, the prosecution 

history regarding a claim limitation in any patent that 

has issued applies with equal force to subsequently issued 

patents that contain the same claim limitation.’” Id. at 

1046 (quoting Elkay Mfg. Co. v. Ebco Mfg. Co., 192 F.3d 

973, 980 (Fed. Cir. 1999)). TT argued that prosecution 

disclaimers affecting the ’132 and ’304 patents should not 

automatically limit the ’055 patent, with its distinct and 

 5 In addition to the ’055 patent, the district court 

applied prosecution history estoppel to two other related 

TT patents, but those patents are not included in this 

appeal. 
14 TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC

contravening additional disclosures, but the district court 

disagreed. “That the ’055 patent is only a continuation-inpart makes no difference.” Id. at 1047 n.15. The district 

court therefore held that TT was estopped from asserting 

that any claims of the ’055 patent were infringed under 

the doctrine of equivalents by a product with a price axis 

that moves automatically. Id. at 1048. 

Following the Summary Judgment Order, the district 

court held a status hearing and ordered the parties to file 

a joint response summarizing the effects of its ruling on 

each patent in suit. The parties agreed that the decision 

had rendered the following claims invalid: all claims of 

the ’411 patent except claim 15, all claims of the ’768 

patent, and all claims of the ’374 patent except claims 7 

and 11. The parties disagreed, however, on the status of 

the ’055 patent. The Defendants contended that, in view 

of eSpeed, the ’055 patent claims remained valid but 

limited in scope. TT maintained that the ’055 patent’s 

added disclosures ascribed a different meaning to “static” 

in that patent relative to those at issue in eSpeed. Therefore, TT asserted, the district court’s Summary Judgment 

Order, which relied on eSpeed, should not affect the ’055 

patent for purposes of prosecution history estoppel or 

otherwise. 

The district court issued a subsequent order denying 

TT’s motion to reconsider the prosecution history estoppel 

ruling, extending its invalidity holding, and certifying 

partial judgment for immediate appeal. Trading Techs. 

Int’l, Inc. v. BCG Partners, Inc., 883 F. Supp. 2d 772 (N.D. 

Ill. 2012) (“Certification Order”). Specifically, the court 

reaffirmed its conclusion that prosecution history estoppel 

applied to the ’055 patent because of eSpeed despite the 

’055 patent’s distinct disclosures and prosecution history 

as a continuation-in-part. Id. at 778–79. And having 

concluded that eSpeed applied to the ’055 patent, the 

court decided that its Summary Judgment Order rendered the ’055 patent invalid. Certification Order, 883 F. 
TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC 15

Supp. 2d at 781 n.1. The district court also agreed with 

both parties that its earlier order had largely invalidated 

the ’768 and ’374 patents as well. Id. at 782–84. Finally, 

the court found no just reason to delay an appeal as to 

those issues and therefore entered partial final judgment 

pursuant to Federal Rule of Civil Procedure 54(b).6

TT filed a timely appeal, and we have jurisdiction under 28 U.S.C. § 1295(a)(1). 

DISCUSSION

 Summary judgment is appropriate “if the movant 

shows that there is no genuine dispute as to any material 

fact and the movant is entitled to judgment as a matter of 

law.” Fed. R. Civ. P. 56(a). We apply the law of the 

regional circuit when reviewing a district court’s entry of 

summary judgment. Teva Pharm. Indus., Ltd. v. AstraZeneca Pharm. LP, 661 F.3d 1378, 1381 (Fed. Cir. 2011). 

The Seventh Circuit reviews the grant or denial of summary judgment without deference. Omnicare, Inc. v. 

UnitedHealth Grp., Inc., 629 F.3d 697, 723 (7th Cir. 

2011). “Compliance with the written description requirement is a question of fact but is amenable to summary judgment in cases where no reasonable fact finder 

could return a verdict for the non-moving party.” 

PowerOasis, Inc. v. T-Mobile USA, Inc., 522 F.3d 1299, 

1307 (Fed. Cir. 2008). Prosecution history estoppel operates as a legal limitation on a patentee’s ability to invoke 

 6 The court noted that TT had agreed “to enter into 

a covenant not to sue on any of the remaining valid 

claims of the ’411, ’768, ’374, and ’055 patents.” 

Certification Order, 883 F. Supp. 2d at 782 (emphasis 

added). We interpret the district court’s statements to 

mean that its final judgment invalidated the following 

claims: claims 1–14 and 16–28 of the ’411 patent; all 

claims of the ’768 patent; claims 1–6, 8–10, and 12–36 of 

the ’374 patent; and all claims of the ’055 patent. 
16 TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC

the doctrine of equivalents, and we review its application 

de novo. eSpeed, 595 F.3d at 1355. 

A. Written Description 

As described, the district court granted summary 

judgment in favor of the Defendants as to the invalidity of 

most claims of TT’s ’411, ’768, ’374, and ’055 patents, 

holding that our prior decision in eSpeed rendered those 

claims invalid as a matter of law for failing to satisfy the 

written description requirement of § 112. 

 TT argues that the district court relied on portions of 

eSpeed that dealt solely with interpreting the term “static” in the related ’132 and ’304 patents without determining or addressing the scope of the patents’ shared 

disclosure. Noting that the sufficiency of a patent’s written description presents a question of fact, TT faults the 

district court for relying entirely on eSpeed rather than 

conducting its own analysis of whether any of the claims 

at issue find adequate written description support under 

§ 112. TT contends that, on the merits and apart from 

any misapplication of eSpeed, the claims of the ’411, ’768, 

’374, and ’055 patents satisfy the written description 

requirement. 

 The Defendants respond that the district court 

properly relied on eSpeed because eSpeed’s claim construction analysis turned on the same basic issue as the 

present written description inquiry—whether the original 

’132 patent discloses a display with a price column that 

moves through means other than manual re-centering. 

According to the Defendants, that issue was finally and 

necessarily decided in eSpeed, precluding any contrary 

findings in this case. 

 As explained more fully below, we conclude that the 

district court placed undue reliance on eSpeed in its 

written description analysis and thus erred when it held 
TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC 17

TT’s claims invalid without considering the scope of the 

claims in light of the underlying disclosures. 

1. The ’411, ’768, and ’374 Patents 

 The ’411, ’768, and ’374 patents all rely on the same 

underlying disclosure as the ’132 and ’304 patents discussed in eSpeed. But the claims of the patents now 

before us are different, as are the issues at play, and 

eSpeed’s ruling on claim construction does not govern the 

written description inquiry in this case. 

The question here is whether the patents’ common 

disclosure provides adequate support for claims not 

limited to displays with “static” price axes, i.e., claims 

broad enough to encompass some form of automatic recentering. In explaining its reliance on eSpeed, the district court correctly perceived that the written description 

and claim construction analyses both look to a patent’s 

specification for guidance. See Summary Judgment 

Order, 852 F. Supp. 2d at 1045 (stating that “§ 112 questions and claim construction questions look to the specification first and foremost”). Despite their similarities, 

however, claim construction and the written description 

requirement are separate issues that serve distinct purposes. 

In construing claims, a court seeks to discern the 

meaning of a particular term used in one or more claims 

of a patent, based, inter alia, on evidence drawn from the 

specification, the surrounding claim language, the prosecution history, and relevant extrinsic sources. See generally Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005) 

(en banc). The specification is fundamental to claim 

construction, as “‘it is the single best guide to the meaning 

of a disputed term.’” Id. at 1315 (quoting Vitronics Corp. 

v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996)). 

While guided by the specification, the focus of claim 

construction remains on defining a discrete claim term to 

better ascertain the boundaries of a claim. In contrast, 
18 TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC

the written description analysis considers the bounds of 

the specification itself. The written description requirement prevents patentees from claiming more than they 

have actually invented and disclosed to the public, as 

measured by the written description of the invention 

provided with their patent applications. In other words, 

the written description requirement “ensure[s] that the 

scope of the right to exclude, as set forth in the claims, 

does not overreach the scope of the inventor’s . . . patent 

specification.” Reiffin v. Microsoft Corp., 214 F.3d 1342, 

1345 (Fed. Cir. 2000). 

 This case illustrates the distinction. In eSpeed, we 

were called upon to evaluate the proper construction of 

“static,” a term used in the claims of the ’132 and ’304 

patents. Accordingly, we considered the evidence relevant 

to a proper reading of that term, starting with those 

patents’ common written description. eSpeed, 595 F.3d at 

1353–55. Noting that the patents referred to one-click 

centering as part of the invention and did not discuss 

automatic re-centering, we concluded that the specification “strongly suggests” that a “static” price column would 

require manual re-centering. Id. at 1353–54. And even 

though the patents described price columns that “do not 

normally change positions unless a re-centering command 

is received,” ’132 patent col. 7 ll. 46–48 (emphasis added), 

we concluded that “the inventors jettisoned the word 

‘normally’ during prosecution” by limiting the term “static” in response to an indefiniteness rejection, eSpeed, 595 

F.3d at 1354. In sum, we concluded that the disputed 

claim term should be limited to require a manual recentering command in the claims of the ’132 and ’304 

patents. 

 But our decision in eSpeed did not thereby determine 

whether the same written description would also support 

different claims drawn to a non-“static” display. In particular, we did not make “findings regarding the specification . . . that are dispositive” as to the present written 
TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC 19

description challenge. See Summary Judgment Order, 

852 F. Supp. 2d at 1044. On the contrary, we merely 

determined the best construction for a single disputed 

claim term, a term that is absent from the claims of the 

’411, ’768, and ’374 patents now before us. That analysis 

did not require us to pass on the outer limits of the patents’ written description, nor did we endeavor to do so. 

In fact, our prior examination of that written description 

did not even settle the limited claim construction issue 

then facing the court, see eSpeed, 595 F.3d at 1353–54 

(concluding that the specification “strongly suggests” that 

the claimed re-centering feature is manual), much less 

conclusively find that the same written description could 

never support any claim to a display with a non-“static” 

price axis. 

To be clear, we express no opinion as to whether or 

not the claims of the ’411, ’768, and ’374 patents now 

before us satisfy the written description requirement. We 

leave that determination for the district court to make in 

the first instance based on its own review of the disclosures underlying those particular claims. We hold only 

that eSpeed did not settle the issue, and we therefore 

reverse the district court’s entry of summary judgment of 

invalidity and remand for further proceedings on the 

merits under § 112. 

2. The ’055 Patent 

 The district court devoted scant analysis to the validity of the ’055 patent’s claims, noting summarily that its 

judgment regarding the ’411 patent had also invalidated 

the ’055 patent. Certification Order, 883 F. Supp. 2d at 

782 n.1. For the reasons already set forth, that holding 

was unsound as far as it relied on eSpeed as dispositive of 

validity under the written description requirement in this 

case. But the district court’s invalidity ruling suffers from 

additional problems specific to the ’055 patent. 
20 TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC

In contrast to the ’411, ’768, and ’374 patents, the ’055 

patent was filed as a continuation-in-part application, 

which allowed TT to disclose and claim additional subject 

matter in the ’055 patent. PowerOasis, 522 F.3d at 1304 

n.3 (“[A] continuation-in-part application contain[s] a 

portion or all of the disclosure of an earlier application 

together with added matter not present in that earlier 

application. . . . Generally, a CIP adds new matter on 

which at least one claim relies for support.”); 37 C.F.R. 

§ 1.53(b)(2) (“A continuation-in-part application . . . may 

disclose and claim subject matter not disclosed in the 

prior application . . . .”). 

As such, the ’055 patent differs fundamentally from 

those at issue in eSpeed, and its unique written description was never considered in that case. Furthermore, the 

supplemental disclosures in the ’055 patent are extensive—the ’055 patent’s written description spans thirtyfour printed columns, compared to just eleven in the ’132 

patent—and directly relevant to the written description 

question presented here. For example, the new matter 

added to the ’055 patent includes express descriptions of 

“static” price axes that can automatically re-center based 

on predefined criteria: 

In one embodiment, the trading application tracks 

the market’s activity by automatically centering, 

for example, the inside market . . . on the display 

with respect to a static axis or scale of prices. . . . 

. . . . 

. . . When . . . the inside market line is outside of 

the viewable area of a trader’s display, or is more 

than a predetermined distance away from a location on the display, the . . . inside market line will 

automatically be placed at a predetermined location on the display. 
TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC 21

’055 patent col. 25 ll. 6–38. In turn, those new disclosures 

correspond directly to accompanying claim limitations 

recited in the ’055 patent. See id. col. 34 ll. 60–67 (“automatically repositioning the static price axis on the graphical user interface such that a current inside market price 

is displayed at a new desired location”). 

Given such unambiguous support for claims requiring 

“automatic[] repositioning the static price axis,” it cannot 

be said that the ’055 patent’s written description does not 

“reasonably convey[] to those skilled in the art that the 

inventor had possession of the claimed subject matter as 

of the filing date” of the ’055 patent. Ariad Pharm., Inc. v. 

Eli Lilly & Co., 598 F.3d 1336, 1351 (Fed. Cir. 2010) (en 

banc). We therefore conclude that TT is entitled to summary judgment that the claims of the ’055 patent have not 

been proven invalid by clear and convincing evidence for 

lack of adequate written description. Accordingly, we 

reverse the district court’s summary judgment of invalidity and its denial of TT’s cross-motion regarding the claims 

of the ’055 patent. 

B. Prosecution History Estoppel 

Finally, before holding the claims of the ’055 patent 

invalid under § 112, the district court also held that “TT is 

estopped from asserting that any [claims of the ’055 

patent] can be infringed under the doctrine of equivalents 

by a product that has a price axis that moves automatically or re-centers automatically.” Summary Judgment 

Order, 852 F. Supp. 2d at 1048. According to the district 

court, prosecution history estoppel imposed against the 

’132 and ’304 patents in eSpeed also extended to the later 

’055 patent. Id. at 1046. 

 TT maintains that the new matter added to the ’055 

patent plainly establishes that the claim term “static” has 

a broader meaning in the ’055 patent than in the ’132 and 

’304 patents. In addition, TT asserts that the district 

court committed legal error by holding that prosecution 
22 TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC

history estoppel regarding that term in the ’132 and ’304 

patents necessarily applies to all of their progeny, including the continuation-in-part ’055 patent. 

 The Defendants answer that eSpeed included a binding legal determination regarding the prosecution history 

of the “static” claim limitation in the TT patent family, 

which applies equally to the ’055 patent’s use of that term 

in the same context and in a similar specification. Furthermore, the Defendants suggest that even if TT could 

rescind its earlier disclaimer, the ’055 patent contains 

only vague or ambiguous statements that do not suffice to 

broaden the scope of “static price axis” beyond that established in eSpeed. 

 As an initial matter, although the parties have labeled their disagreement as one pertaining to prosecution 

history estoppel, we note some ambiguity as to whether 

the substance of their arguments and the district court’s 

ruling in fact concerns prosecution history estoppel, 

prosecution disclaimer, or both. Prosecution history 

estoppel applies as part of an infringement analysis to 

prevent a patentee from using the doctrine of equivalents 

to recapture subject matter surrendered from the literal 

scope of a claim during prosecution. Pall Corp. v. Hemasure Inc., 181 F.3d 1305, 1311 (Fed. Cir. 1999). Prosecution disclaimer, on the other hand, affects claim 

construction and applies where an applicant’s actions 

during prosecution prospectively narrow the literal scope 

of an otherwise more expansive claim limitation. Omega 

Eng’g, Inc. v. Raytek Corp., 334 F.3d 1314, 1323–24 (Fed. 

Cir. 2003). Though distinct, both doctrines serve to 

constrain the enforceable scope of patent claims commensurate with any subject matter surrendered during prosecution to obtain the patent, and a single action during 

prosecution can engender both a prosecution disclaimer 

and prosecution history estoppel. See, e.g., Elkay, 192 

F.3d at 978–79, 981; Spectrum Int’l, Inc. v. Sterilite Corp., 

164 F.3d 1372, 1380 (Fed. Cir. 1998). 
TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC 23

 Here, as noted, the district court based its prosecution 

history estoppel analysis on eSpeed. But eSpeed addressed prosecution history estoppel and prosecution 

disclaimer, 595 F.3d at 1357 (noting that “both claim 

construction and prosecution history estoppel operate in 

this case with similar limited results”), and those parallel 

discussions appear to have been conflated in this case. 

The district court found that an amendment inserting 

the term “common static price axis” into the claims of the 

’132 and ’304 patents had driven the prosecution history 

estoppel ruling in eSpeed. Summary Judgment Order, 

852 F. Supp. 2d at 1046 (“[T]he Federal Circuit found that 

inserting the limitation of ‘common static price axis’ into 

the claims of the ’304 patent prevented TT from asserting 

that products with price axes that move automatically . . . 

infringe under the doctrine of equivalents.”). Because the 

’055 patent’s claims include essentially the same limitation, the district court reasoned that the holding in eSpeed

must also apply to the ’055 patent. Id. at 1047 (“Where 

the same claim term is at issue in the same context, TT’s 

disclaimer as to the ’304 patent applies to the [’055 patent].”). But the amendments that gave rise to prosecution history estoppel in eSpeed did not introduce a “static” 

price axis into the claims—that term was already present. 

They instead “clarified that the claimed price levels ‘do 

not move’ when the inside market changes.” eSpeed, 595 

F.3d at 1357. 

Thus, the term “static” (or “common static price axis”) 

itself did not form the basis for our prosecution history 

estoppel determination in eSpeed. Furthermore, the key 

“do not move” language added by amendment to the ’132 

and ’304 patents does not recur in the claims of the ’055 

patent. Alternatively, the issue of prosecution disclaimer 

in eSpeed did turn on discussion of the term “static” 

during prosecution, id. at 1354–55, and, as noted, that 

term does appear in the claims of the ’055 patent. In 

addition, the district court’s opinion and the parties’ 
24 TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC

briefing before this court variously touch on claim construction while ostensibly discussing prosecution history 

estoppel. See, e.g., Summary Judgment Order, 852 F. 

Supp. 2d at 1047 (summarizing relevant authorities as 

“concerned about consistency of constructing claims”); 

Appellant’s Br. 41 (“[T]he dispositive issue is whether the 

term has the same meaning.”). 

 Regardless, whether viewed through the lens of 

prosecution history estoppel or prosecution disclaimer, the 

basic question here is whether TT’s earlier prosecutionbased “surrender[] [of] any subject matter that moves 

automatically,” eSpeed, 595 F.3d at 1357, carries through 

from the ’132 and ’304 patents to limit the enforceable 

scope of the ’055 continuation-in-part. We hold that it 

does not. 

 Prosecution history estoppel can extend from a parent 

application to subsequent patents in the same lineage, 

Elkay, 192 F.3d at 981, as can a prosecution disclaimer, 

Omega Eng’g, 334 F.3d at 1333–34. But “arguments 

made in a related application do not automatically apply 

to different claims in a separate application.” Biogen, Inc. 

v. Berlex Labs., Inc., 318 F.3d 1132, 1139 (Fed. Cir. 2003). 

In general, the prosecution history regarding a particular 

limitation in one patent is presumed to inform the later 

use of that same limitation in related patents, “unless 

otherwise compelled.” Omega Eng’g, 334 F.3d at 1334. 

 In this case, the intrinsic record specific to the ’055 

patent distinguishes eSpeed and compels a different 

result. The ’055 patent, as a continuation-in-part of the 

’132 patent, includes extensive disclosures that were not 

present in the ’132 or ’304 patents, and those subsequent 

disclosures directly contradict the prosecution-based 

surrenders of claim scope discussed in eSpeed. For example, the ’055 patent states that “static does not mean 

immovable,” ’055 patent col. 4 l. 54, and describes “automatically repositioning the static price axis upon detect-
TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC 25

ing a predetermined condition,” id. col. 3 ll. 19–20. Furthermore, the claims of the ’055 patent lack the “do not 

move” limitations that accompanied the term “static” in 

the ’132 and ’304 patents. See eSpeed, 595 F.3d 1356–57. 

Rather, the claims of the ’055 patent contain express 

language requiring automatic movement of the static 

price axis. ’055 patent col. 34 ll. 60–67. Finally, TT made 

clear during prosecution of the ’055 patent—before the 

same examiner who had handled the ’132 and ’304 patents—that the “static” price axis described and claimed 

in the ’055 patent was not limited to manual re-centering. 

While it retains the “static price axis” claim language 

of its predecessors, the ’055 patent thus differs from the 

’132 and ’304 patents in both its claims and its relevant 

supporting disclosures on the issue of automatic recentering. Those differences render eSpeed’s earlier 

prosecution-based restrictions inapplicable to the ’055 

patent. See Middleton, Inc. v. Minn. Mining & Mfg. Co., 

311 F.3d 1384, 1389 (Fed. Cir. 2002). “When the purported disclaimers are directed to specific claim terms that 

have been omitted or materially altered in subsequent 

applications . . . those disclaimers do not apply.” Saunders Grp., Inc. v. Comfortrac, Inc., 492 F.3d 1326, 1333 

(Fed. Cir. 2007). Accordingly, the claims of the ’055 

patent, unlike those of the related ’132 and ’304 patents, 

need not be limited to displays with price axes capable 

only of manual re-centering, whether by prosecution 

disclaimer or prosecution history estoppel. The district 

court’s decisions (i) granting summary judgment that 

prosecution history estoppel applies to the ’055 patent, 

and (ii) denying TT’s cross-motion, are reversed. 

CONCLUSION

 As explained above, we conclude that eSpeed does not 

govern the issues of written description or prosecution 

history estoppel raised in this appeal. We reverse and 
26 TRADING TECHNOLOGIES INTL v. OPEN E CRY, LLC

remand for further proceedings consistent with this 

opinion. 

REVERSED AND REMANDED