MAGNITE, INC. — Director's Dealing 2016

May 17, 2016

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: RUBICON PROJECT, INC. (RUBI)
CIK: 0001595974
Period of Report: 2016-05-15

Reporting Person: Day David (Chief Accounting Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2016-05-15	Common Stock	F	2948	$14.31	Disposed	78808	Direct
2016-05-16	Common Stock	S	10819	$14.22	Disposed	67989	Direct

Footnotes

F1: Shares withheld by the issuer to cover the reporting person's tax liability incurred upon the vesting of the reporting person's restricted shares.

F2: Includes 1,250 shares acquired under the The Rubicon Project, Inc. 2014 Employee Stock Purchase Plan on May 15, 2016.

F3: The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan. A portion of the shares were sold in order to cover the reporting person's tax liability incurred upon the vesting of the reporting person's restricted shares.

F4: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $14.02 to $14.35, inclusive. The reporting person undertakes to provide The Rubicon Project, Inc., any security holder of The Rubicon Project, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnote 4 to this Form 4.