Rambus (RMBS) CEO Seraphin Luc logs PRSU award and tax share withholding

Rhea-AI Filing Summary

Rambus Inc. President and CEO Seraphin Luc reported equity compensation and related tax withholding in company stock. On February 1, 2026, he acquired 143,744 shares of common stock at $0 per share, represented by performance restricted stock units that vest based on company performance metrics and continued service through February 1, 2026.

On the same date, 92,523 shares of common stock were withheld at a price of $113.71 per share to satisfy his tax liability arising from the vesting of restricted stock units. After these transactions, he directly beneficially owned 370,984 shares of Rambus common stock, including 522 shares acquired through the Rambus Inc. 2015 Employee Stock Purchase Plan.

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

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Seraphin Luc

(Last) (First) (Middle)

C/O RAMBUS INC.

4453 NORTH FIRST STREET, SUITE 100

(Street)

SAN JOSE CA 95134

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
RAMBUS INC [ RMBS ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	President and CEO

3. Date of Earliest Transaction (Month/Day/Year)
02/01/2026

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	02/01/2026		A		143,744(1)	A	$0	463,507(2)	D
Common Stock	02/01/2026		F(3)		92,523	D	$113.71	370,984	D

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. The shares are represented by performance restricted stock units, or PRSUs, all of which vest on February 1, 2026 based upon assessed achievement of the Company's performance metrics and continued service to the Company through the vesting date. Each PRSU represents a contingent right to receive one share of RMBS common stock.

2. Includes an exempt transaction of 522 shares acquired through the Rambus Inc. 2015 Employee Stock Purchase Plan.

3. The shares were withheld to cover the Reporting Person's tax liability in connection with the vesting of restricted stock units, or RSUs.

	/s/ Brian Wu, by power of attorney	02/03/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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FAQ

What transactions did Rambus (RMBS) CEO Seraphin Luc report on February 1, 2026?

Seraphin Luc reported receiving 143,744 Rambus common shares at $0 per share and a withholding of 92,523 shares at $113.71 per share. The withholding covered tax obligations from restricted stock unit vesting, and all positions are reported as directly owned common stock.

How many Rambus (RMBS) shares does Seraphin Luc own after the reported Form 4 transactions?

After the February 1, 2026 transactions, Seraphin Luc beneficially owned 370,984 shares of Rambus common stock directly. This total includes 522 shares acquired through the Rambus Inc. 2015 Employee Stock Purchase Plan, as disclosed in the Form 4 explanatory footnotes.

What type of equity award did Rambus (RMBS) grant to CEO Seraphin Luc on February 1, 2026?

The award is represented by 143,744 performance restricted stock units, or PRSUs, each linked to one share of Rambus common stock. All PRSUs vest on February 1, 2026, based on assessed achievement of company performance metrics and continued employment through the vesting date.

Why were 92,523 Rambus (RMBS) shares withheld from Seraphin Luc on February 1, 2026?

92,523 shares were withheld to cover Seraphin Luc’s tax liability arising from the vesting of restricted stock units, or RSUs. The shares are reported as a disposition at $113.71 per share and are characterized as tax-withholding rather than an open-market sale.

What does the performance condition on Seraphin Luc’s Rambus (RMBS) PRSUs involve?

The performance restricted stock units vest based on Rambus’ assessed achievement of its performance metrics and Seraphin Luc’s continued service through February 1, 2026. Each vested PRSU entitles him to receive one share of Rambus common stock upon satisfaction of these conditions.

How are employee stock purchase plan shares reflected in Seraphin Luc’s Rambus (RMBS) holdings?

His reported holdings include an exempt acquisition of 522 shares through the Rambus Inc. 2015 Employee Stock Purchase Plan. These plan shares are part of his total directly beneficially owned 370,984 Rambus common shares reported after the February 1, 2026 transactions.