SEC Form 4
FORM 4 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number: 3235-0287
Estimated average burden
hours per response: 0.5
  
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
1. Name and Address of Reporting Person*
Mandal Sumant

(Last) (First) (Middle)
725 ARIZONA AVENUE
SUITE 304

(Street)
SANTA MONICA CA 90401

(City) (State) (Zip)
2. Issuer Name and Ticker or Trading Symbol
RUBICON PROJECT, INC. [ RUBI ]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
X Director X 10% Owner
Officer (give title below) Other (specify below)
3. Date of Earliest Transaction (Month/Day/Year)
05/26/2015
4. If Amendment, Date of Original Filed (Month/Day/Year)
6. Individual or Joint/Group Filing (Check Applicable Line)
X Form filed by One Reporting Person
Form filed by More than One Reporting Person
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4)
Code V Amount (A) or (D) Price
Common Stock, par value $0.00001 per share 05/26/2015 J(1) 618,934 D $17.4 5,744,720(2) I By Clearstone Venture Management III, L.L.C.
Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 6. Date Exercisable and Expiration Date (Month/Day/Year) 7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Explanation of Responses:
1. Distribution of shares to limited partners of Clearstone Venture Partners III-A, L.P., a Delaware Limited Partnership
2. Indirect holdings include 5,570,405 shares directly beneficially owned by Clearstone Venture Partners III-A, L.P., a Delaware Limited Partnership ("CVP III-A") and 110,640 directly beneficially owned by Clearstone Venture Partners III-B, a Delaware multi-series Limited Liability Corporation ("CVP III-B"). Mr. Mandal is a Managing Member of Clearstone Venture Management III, L.L.C., a Delaware Limited Liability Corporation ("CVM III") and shares voting and investment power over shares held beneficially by CVM III. CVM III is the general partner and managing member of CVP III-A and CVP III-B, respectively. Each of the reporting persons disclaims beneficial ownership of such shares of common stock of RUBI to the extent it exceeds its pecuniary interest. Mr. Mandal also has direct ownership of 21,283 common shares received in a restricted stock grant as well as 42,392 common stock options all of which are subject to vesting.
Sumant Mandal 05/27/2015
** 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 4 (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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.