SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person* Charles River Partnership XIII, LP (Last) (First) (Middle) 1000 WINTER STREET SUITE 3300 (Street) WALTHAM MA 02451 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 05/03/2011	3. Issuer Name and Ticker or Trading Symbol RPX Corp [ RPXC ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)	5. If Amendment, Date of Original Filed (Month/Day/Year)
			6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Series A Preferred Stock	(1)	(1)	Common Stock(1)	3,448,276(2)	(1)	D(3)
Series A-1 Preferred Stock	(4)	(4)	Common Stock(4)	3,466,445(5)	(4)	D(3)
Series B Preferred Stock	(6)	(6)	Common Stock(6)	1,574,003(7)	(6)	D(3)
Series C Preferred Stock	(8)	(8)	Common Stock(8)	109,255(9)	(8)	D(3)

1. Name and Address of Reporting Person* Charles River Partnership XIII, LP (Last) (First) (Middle) 1000 WINTER STREET SUITE 3300 (Street) WALTHAM MA 02451 (City) (State) (Zip)

1. Name and Address of Reporting Person* Charles River XIII GP, LP (Last) (First) (Middle) 1000 WINTER STREET SUITE 3300 (Street) WALTHAM MA 02451 (City) (State) (Zip)

1. Name and Address of Reporting Person* Charles River XIII GP, LLC (Last) (First) (Middle) 1000 WINTER STREET SUITE 3300 (Street) WALTHAM MA 02451 (City) (State) (Zip)

Explanation of Responses:

1. Effective upon the issuer's sale of its common stock in its initial public offering, each share of Series A convertible preferred stock will automatically convert into 1 share of common stock. The Series A convertible preferred stock has no expiration date.

2. Represents 3,354,132 shares held by Charles River Partnership XIII, LP ("CRP XIII") and 94,144 shares held by Charles River Friends XIII-A, LP ("CRF XIII-A"). CRP XIII and CRF XIII-A form a "group" for purposes of Section 13(d) of the Securities Exchange Act of 1934.

3. Charles River XIII GP, LP ("CR XIII GP LP") is the general partner of CRP XIII; Charles River XIII GP, LLC ("CR XIII GP LLC") is the general partner of both CRF XIII-A and CR XIII GP LP. Each of CR XIII GP LP and CR XIII GP LLC may be deemed to beneficially own the reported securities, but each disclaims beneficial ownership of the reported securities except to the extent of its pecuniary interest therein. The filing of this statement by any reporting person shall not be deemed an admission that such person is, for purposes of Section 16 of the Securities Exchange Act of 1934 or otherwise, the beneficial owner of any equity securities covered by this statement.

4. Effective upon the issuer's sale of its common stock in its initial public offering, each Share of Series A-1 convertible preferred stock will automatically convert into 1 share of common stock. The Series A-1 convertible preferred stock has no expiration date.

5. Represents 3,371,805 shares held by CRP XIII and 94,640 shares held by CRF XIII-A.

6. Effective upon the issuer's sale of its common stock in its initial public offering, each share of Series B convertible preferred stock will automatically convert into 1 share of common stock. The Series B convertible preferred stock has no expiration date.

7. Represents 1,531,030 shares held by CRP XIII and 42,973 shares held by CRF XIII-A.

8. Effective upon the issuer's sale of its common stock in its initial public offering, each share of Series C convertible preferred stock will automatically convert into 1 share of common stock. The Series C convertible preferred stock has no expiration date.

9. Represents 106,272 shares held by CRP XIII and 2,983 shares held by CRF XIII-A.

	Sarah Reed as Attorney-in-Fact for Charles River Partnership XIII, LP	05/03/2011
	Sarah Reed as Attorney-in-Fact for Charles River XIII GP, LP	05/03/2011
	Sarah Reed as Attorney-in-Fact for Charles River XIII GP, LLC	05/03/2011
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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