California BanCorp chair’s tax-withholding trade shows minimal impact

Rhea-AI Filing Summary

California BanCorp (BCAL) Form 4 filing, 08/04/2025: Executive Chairman and Director David I. Rainer satisfied tax-withholding obligations by having 3,508 BCAL common shares withheld on 08/02/2025 (Transaction Code F). The shares were valued at $14.60 each, an implied transaction value of roughly $51 k. Because Code F denotes shares withheld from a vested equity award, the sale was not an open-market disposition.

After the withholding, Rainer still directly owns 200,004 shares and indirectly, through the David and Anne Rainer Trust, another 329,124 shares, for a total beneficial ownership of about 529 k shares. His ownership percentage and board/management roles remain unchanged.

No derivatives were reported, and no other transactions occurred. Given the small size relative to his total position and the administrative nature of the trade, the filing is unlikely to have a material impact on BCAL’s governance, capital structure, or market sentiment.

Positive

• Insider still holds approx. 529 k shares, indicating continued alignment with shareholders.

Negative

• 3,508 shares were disposed (albeit for tax withholding), a slight reduction in insider ownership.

Insights

Securities Analyst

TL;DR Minor tax-withholding sale; insider retains >500k shares, so negligible strategic signal.

The F-code transaction shows Rainer met tax liabilities from a vesting event. Only ~0.7 % of his total stake was surrendered, preserving substantial insider alignment. Such routine Form 4s rarely affect valuation unless volumes are large or pattern suggests distribution, which is not the case here. I view the impact on BCAL’s stock sentiment as neutral.

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).

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^*

Rainer David I

(Last) (First) (Middle)

C/O CALIFORNIA BANCORP

355 S. GRAND AVE STE 1200

(Street)

LOS ANGELES CA 90071

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
California BanCorp \ CA [ BCAL ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
08/02/2025

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	08/02/2025		F(1)		3,508	D	$14.6	200,004	D
Common Stock								329,124	I	DAVID AND ANNE RAINER TRUST U/A DTD 05/07/1997

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. Shares disposed to satisfy the Reporting Person's tax liability by the vesting of a previously granted award.

Remarks:

	Manisha Merchant, by POA for Rainer David	08/04/2025
	** 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 did BCAL Executive Chairman David Rainer report on Form 4?

He had 3,508 shares withheld on 08/02/2025 to pay taxes on a vesting award.

Was the transaction an open-market sale?

No. Transaction Code F indicates share withholding for taxes, not a market sale.

How many BCAL shares does Rainer now own?

Post-transaction he owns 200,004 shares directly and 329,124 shares indirectly via trust.

Does this filing change Rainer’s role at California BanCorp?

No, he remains Executive Chairman and Director.

Is the sale material to BCAL investors?

Given the small size (~$51 k) relative to total holdings, the impact is considered immaterial.