UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

(Rule 14a-101)

INFORMATION REQUIRED IN PROXY STATEMENT

SCHEDULE 14A INFORMATION

Proxy Statement Pursuant to Section 14(a) of The Securities Exchange Act of 1934

(Amendment No. )

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ACACIA RESEARCH CORPORATION

(Name of Registrant as Specified in Its Charter)

SIDUS INVESTMENT PARTNERS, L.P.

SIDUS DOUBLE ALPHA FUND, L.P.

SIDUS DOUBLE ALPHA, LTD.

SIDUS ADVISORS, LLC

SIDUS INVESTMENT MANAGEMENT, LLC

MICHAEL J. BARONE

ALFRED V. TOBIA JR.

BLR PARTNERS LP

BLRPART, LP

BLRGP INC.

FONDREN MANAGEMENT, LP

FMLP INC.

BRADLEY L. RADOFF

Clifford Press

(Name of Persons(s) Filing Proxy Statement, if Other Than the Registrant)

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Sidus Investment Management, LLC and BLR Partners LP, together with the other participants named herein (collectively, “Sidus”), has made a definitive filing with the Securities and Exchange Commission of a proxy statement and accompanying BLUE proxy card to be used to solicit votes for the election of Sidus’ slate of highly qualified director nominees to the Board of Directors of Acacia Research Corporation, a Delaware corporation (the “Company”), at the Company’s upcoming 2018 annual meeting of stockholders, or any other meeting of stockholders held in lieu thereof, and any adjournments, postponements, reschedulings or continuations thereof.

On May 17, 2018, Sidus mailed the following material to the Company’s stockholders: