[Form 4] California BanCorp Insider Trading Activity

Rhea-AI Filing Summary

David I. Rainer, Executive Chairman and Director of California BanCorp (BCAL), reported insider dispositions on 08/27/2025. The Form 4 shows a disposition of 6,300 common shares at $16.7216 and a separate disposition of 200,004 common shares. The filing reports 322,824 shares beneficially owned following the reported transactions, held indirectly through the David and Anne Rainer Trust U/A dated 05/07/1997. The form was signed by a POA on 08/28/2025.

Positive

• None.

Negative

• Insider dispositions totaling 206,304 shares were reported, which could be viewed negatively by some investors seeking insider buying signals
• One sizable disposition of 200,004 shares is material in absolute terms and reduces the insider's reported economic exposure

Insights

Financial Analyst

TL;DR: Insider sold a substantial block of shares; transaction size may modestly affect float but no earnings or guidance changes.

The report documents two dispositions totaling 206,304 shares on 08/27/2025, including a priced sale of 6,300 shares at $16.7216. Beneficial ownership after the transactions is reported as 322,824 shares held indirectly. For investors, this is a disclosure of insider liquidity rather than operational news; the filing does not state purpose or indicate change in role.

Corporate Governance Expert

TL;DR: Routine insider disposition reported; ownership remains held indirectly via trust with POA signature.

The filer is identified as Executive Chairman and Director, and the beneficial holding remains through the David and Anne Rainer Trust. The Form 4 was executed by a power of attorney, which is standard. The filing contains no statements of change in employment or control, so governance impact appears limited to transparency about insider sales.

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)
08/27/2025

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	08/27/2025		D		6,300	D	$16.7216	322,824	I	DAVID AND ANNE RAINER TRUST U/A DTD 05/07/1997
Common Stock								200,004	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:

Remarks:

	Manisha Merchant, by POA for David Rainer	08/28/2025
	** 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 transactions did David I. Rainer report on Form 4 for BCAL?

He reported dispositions on 08/27/2025: a sale of 6,300 shares at $16.7216 and a separate disposition of 200,004 shares.

How many BCAL shares does David I. Rainer beneficially own after the reported transactions?

The Form 4 reports 322,824 shares beneficially owned following the reported transactions, held indirectly via a trust.

What is David I. Rainer's role at California BanCorp (BCAL)?

The filing identifies him as Executive Chairman and a Director of the issuer.

Who signed the Form 4 and when was it signed?

The Form 4 was signed by Manisha Merchant, by POA for David Rainer on 08/28/2025.