Cerus (CERS) CEO sells 447,757 shares under 10b5-1 tax plan

Rhea-AI Filing Summary

CERUS CORP President and CEO William Mariner Greenman reported an open-market sale of 447,757 shares of common stock on March 12, 2026 at a weighted average price of $1.6572 per share. The footnotes state the instruction was intended to comply with Rule 10b5-1 and was elected on the grant date to cover statutory tax withholding obligations and brokerage fees tied to the vesting of restricted stock units, so it was not a discretionary sale. After this transaction, he directly owned 4,998,493 shares of Cerus common stock.

Insider Trade Summary 10b5-1

Net Seller: 447,757 shares ($742,023)

Net Sell 1 txn

Insider Greenman William Mariner

Role President and CEO

Sold 447,757 shs ($742K)

Type	Security	Shares	Price	Value
Sale	Common Stock	447,757	$1.6572	$742K

Holdings After Transaction: Common Stock — 4,998,493 shares (Direct)

Footnotes (1)

1. Represents shares sold pursuant to an instruction intended to comply with the requirement of Rule 10b5-1 that was elected by the Reporting Person on the date of grant to cover statutory tax withholding obligations and corresponding brokerage fees in connection with the vesting of certain restricted stock units and does not represent a discretionary sale by the reporting person. Represents a weighted average sales price. These shares were sold in multiple transactions at prices ranging from $1.62 to $1.73 per share, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, 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 aforementioned range set forth.

Form 4 Insider Transactions: What Each Field Means →

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).

X

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^*

Greenman William Mariner

(Last) (First) (Middle)

C/O CERUS CORPORATION

1220 CONCORD AVE SUITE 600

(Street)

CONCORD CA 94520

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
CERUS CORP [ CERS ]

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)
03/12/2026

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	03/12/2026		S		447,757(1)	D	$1.6572(2)	4,998,493	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. Represents shares sold pursuant to an instruction intended to comply with the requirement of Rule 10b5-1 that was elected by the Reporting Person on the date of grant to cover statutory tax withholding obligations and corresponding brokerage fees in connection with the vesting of certain restricted stock units and does not represent a discretionary sale by the reporting person.

2. Represents a weighted average sales price. These shares were sold in multiple transactions at prices ranging from $1.62 to $1.73 per share, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, 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 aforementioned range set forth.

	William M. Greenman, by Chrystal N. Jensen, attorney-in-fact	03/16/2026
	** 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.

FAQ

What insider transaction did CERUS CORP (CERS) report for William Mariner Greenman?

CERUS CORP reported that President and CEO William Mariner Greenman sold 447,757 shares of common stock. The transaction was an open-market sale executed under a Rule 10b5-1 instruction related to tax withholding and brokerage fees from vesting restricted stock units.

At what price did the CERUS CORP CEO’s Form 4 sale occur?

The CERUS CORP CEO’s sale had a weighted average price of $1.6572 per share. Footnotes explain the shares were sold in multiple trades between $1.62 and $1.73 per share, with detailed trade breakdowns available upon request to the company or regulators.

How many CERUS CORP shares does William Mariner Greenman own after this Form 4 transaction?

Following the reported sale, William Mariner Greenman directly owned 4,998,493 shares of CERUS CORP common stock. This post-transaction holding reflects his remaining direct equity position after selling 447,757 shares in connection with tax withholding obligations and related brokerage fees.

Was the CERUS CORP CEO’s sale of shares a discretionary insider trade?

The sale was not described as discretionary. Footnotes state the shares were sold under an instruction intended to comply with Rule 10b5-1, elected on the grant date specifically to cover statutory tax withholding obligations and brokerage fees on vesting restricted stock units.

What does the Rule 10b5-1 reference mean in the CERUS CORP Form 4 filing?

The Rule 10b5-1 reference indicates the sale followed a pre-set instruction established earlier by the CEO. This instruction was designed to satisfy tax withholding and brokerage costs from restricted stock unit vesting, reducing the significance of timing compared with an opportunistic, discretionary sale.

How large was the CERUS CORP CEO’s share sale compared with his remaining holdings?

He sold 447,757 shares and retained 4,998,493 shares afterward. This shows the transaction covered tax-related obligations from restricted stock unit vesting while leaving a substantially larger remaining direct ownership position in CERUS CORP common stock after the Form 4 transaction.