MAGNITE, INC. — Director's Dealing 2017

May 26, 2017

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: RUBICON PROJECT, INC. (RUBI)
CIK: 0001595974
Period of Report: 2017-05-23

Reporting Person: Mandal Sumant (Director)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2017-05-23	Common Stock	A	7292	—	Acquired	32458	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2017-05-23	Stock Option (right to buy)	$5.17	A	10363	Acquired	2027-05-23	Common Stock (10363.0)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	3075794	Indirect

Footnotes

F1: Represents restricted stock units that vest in full on the earliest of (i) May 23, 2018, (ii) the date of the next Annual Meeting of the Issuer's stockholders, or (iii) a change of control of the Issuer.

F2: Granted as compensation for services.

F3: Represents (i) 3,010,692 Shares directly beneficially owned by Clearstone Venture Partners III-A, L.P., a Delaware limited partnership ("CVP III-A"), (ii) 53,819 Shares directly beneficially owned by Clearstone Venture Partners III-B, a Delaware Multiple Series limited liability company ("CVP III-B" and together with CVP III-A, the "Funds"), and (iii) 11,283 Shares directly beneficially owned by Clearstone Venture Management III, L.L.C., a Delaware limited liability company ("CVM III"). CVM III is the general partner and managing member of CVP III-A and CVP III-B, respectively. The reporting person is a managing member of CVM III and a member of CVP III-B.

F4: The reporting person disclaims beneficial ownership of the Shares held by the Funds and CVM III, except to the extent of his pecuniary interest therein, if any, and the inclusion of these Shares in the report shall not be deemed an admission of beneficial ownership of the reported shares for purposes of Section 16 or for any other purposes.

F5: The stock options vest in full on the earliest of (i) May 23, 2018, (ii) the date of the next Annual Meeting of the Issuer's stockholders, or (iii) a change of control of the Issuer.