Eli Casdin boosts equity stake in STANDARD BIOTOOLS (LAB) with 52,991 RSUs

Rhea-AI Filing Summary

Casdin Eli reported acquisition or exercise transactions in this Form 4 filing.

STANDARD BIOTOOLS INC. director and 10% owner Eli Casdin received 52,991 restricted stock units on the company’s common stock at $1.17 per share equivalent. The RSUs vest in four equal 25% installments on the last day of the last month of each fiscal quarter of 2026, conditioned on his continued board service. Casdin elected to receive these RSUs instead of $62,000 in cash compensation for board work. After this grant, he directly holds 2,954,053 common shares or equivalents, and investment funds associated with him hold additional indirect positions through Casdin Private Growth Equity Fund II, L.P., Casdin Private Growth Equity Fund, L.P., and Casdin Partners Master Fund, L.P.

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^*

Casdin Eli

(Last) (First) (Middle)

C/O STANDARD BIOTOOLS INC.

50 MILK STREET, 10TH FLOOR

(Street)

BOSTON MA 02109

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
STANDARD BIOTOOLS INC. [ LAB ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
02/26/2026

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	02/26/2026		A		52,991(1)	A	$1.17	2,954,053(2)	D
Common Stock								13,939,637	I	Casdin Private Growth Equity Fund II, L.P.(3)
Common Stock								2,744,219	I	By Casdin Private Growth Equity Fund, L.P.(4)
Common Stock								72,100,000	I	Casdin Partners Master Fund, L.P.(5)

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 Restricted Stock Units ("RSUs") that vest as to 25% on the last day of the last month of each fiscal quarter of 2026, subject to the Reporting Person's continued service through the applicable vesting date.

2. The RSUs were issued to the Reporting Person, who elected to take RSUs in lieu of $62,000 in cash compensation for services as a board member.

3. The securities are owned directly by Casdin Private Growth Equity Fund II, L.P. (the "Equity Fund II") and may be deemed to be indirectly beneficially owned by (i) Casdin Capital, LLC ("Casdin"), the investment adviser to the Equity Fund II, and (ii) Eli Casdin, the managing member of Casdin.

4. The securities are owned directly by Casdin Private Growth Equity Fund, L.P. (the "Equity Fund") and may be deemed to be indirectly beneficially owned by (i) Casdin, the investment adviser to the Equity Fund, and (ii) Eli Casdin, the managing member of Casdin.

5. The securities are owned directly by Casdin Partners Master Fund, L.P. (the "Master Fund") and may be deemed to be indirectly beneficially owned by (i) Casdin, the investment adviser to the Master Fund, (ii) Casdin Partners GP, LLC, the general partner of the Master Fund (the "GP"), and (iii) Eli Casdin, the managing member of Casdin and the GP.

Remarks:

The Reporting Person disclaims beneficial ownership in the securities reported on this Form 4 except to the extent of his pecuniary interest, if any, therein, and this report shall not be deemed to be an admission that the Reporting Person is the beneficial owner of such securities for purposes of Section 16 or for any other purpose.

	/s/ Eli Casdin	03/02/2026
	** 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 did Eli Casdin report in this Form 4 for STANDARD BIOTOOLS (LAB)?

Eli Casdin reported receiving 52,991 restricted stock units tied to STANDARD BIOTOOLS common stock. The award reflects compensation for his service as a board member, taken in equity instead of cash, and increases his directly held stake in the company.

How many RSUs did Eli Casdin receive and what is their value?

He received 52,991 RSUs valued at $1.17 per share equivalent. The award replaced $62,000 in cash board compensation, meaning his director fees are being paid largely in equity rather than cash for this period of service.

What is the vesting schedule for Eli Casdin’s 52,991 RSUs at STANDARD BIOTOOLS (LAB)?

The RSUs vest in four equal 25% tranches during 2026. Each tranche vests on the last day of the last month of each fiscal quarter, provided Casdin continues serving on the board through each respective vesting date.

How many STANDARD BIOTOOLS (LAB) shares does Eli Casdin hold directly after this grant?

After the RSU award, Eli Casdin directly holds 2,954,053 common shares or equivalents. This reflects his personal stake as reported in the Form 4, separate from larger holdings held through various investment funds he is associated with.

What indirect holdings related to STANDARD BIOTOOLS (LAB) are associated with Eli Casdin?

Indirect holdings are reported through Casdin Private Growth Equity Fund II, L.P., Casdin Private Growth Equity Fund, L.P., and Casdin Partners Master Fund, L.P. These securities are owned by the funds and may be deemed beneficially owned by Casdin through his roles with the adviser entities.

Why did Eli Casdin receive RSUs instead of cash compensation from STANDARD BIOTOOLS (LAB)?

Casdin elected to take RSUs instead of $62,000 in cash board compensation. This choice shifts his remuneration toward equity, aligning a portion of his pay directly with STANDARD BIOTOOLS’ share performance rather than immediate cash income.