[Form 4] BioAtla, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Richard A. Waldron, Chief Financial Officer of BioAtla, Inc. (BCAB), reported a transaction dated 08/31/2025 in which 2,371 shares of common stock were disposed of under code F(1) at a price of $0.4555 per share. The filing states these shares were withheld by the issuer to satisfy income tax withholding and remittance obligations related to the vesting and net settlement of previously reported restricted stock units. Following the withholding, the reporting person beneficially owns 338,521 shares (direct ownership). The Form 4 was filed by one reporting person and signed by an attorney-in-fact on 09/02/2025.

Positive

• Transaction clearly disclosed as a tax withholding for vested restricted stock units, including code F(1), price, and date
• Post-transaction beneficial ownership specified: 338,521 shares (direct)
• Form filed and signed (attorney-in-fact signature dated 09/02/2025), meeting reporting protocol

Negative

• None.

Insights

Securities Analyst

TL;DR: Routine insider withholding for vested RSUs; small, non-sale disposition documented.

This Form 4 documents a tax-withholding disposition (code F(1)) of 2,371 shares related to the vesting and net settlement of previously reported restricted stock units. The report shows the reporting person retains beneficial ownership of 338,521 shares after the withholding. The transaction is recorded as a disposition but is explicitly described as a withholding to satisfy tax obligations rather than an open-market sale, which is a common administrative step following equity vesting.

Corporate Governance Expert

TL;DR: Administrative equity withholding recorded; disclosure meets Section 16 reporting requirements.

The filing clearly identifies the nature of the transaction as issuer-withheld shares to cover tax withholding on vested RSUs, includes the transaction code F(1), the per-share price of $0.4555, the date of transaction, and the post-transaction beneficial ownership. The Form is signed by an attorney-in-fact and filed as a single reporting person submission, providing the required transparency for insider compensation-related equity events.

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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OMB Number:			3235-0287
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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^*

WALDRON RICHARD A

(Last) (First) (Middle)

C/O BIOATLA, INC. 11085 TORREYANA ROAD

(Street)

SAN DIEGO CA 92121

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
BioAtla, Inc. [ BCAB ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
08/31/2025

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	08/31/2025		F(1)		2,371	D	$0.4555	338,521	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. This transaction is not a sale of shares by the Reporting Person. Instead, this represents shares that have been withheld by the Issuer to satisfy its income tax and withholding and remittance obligations in connection with the vesting and net settlement of previously reported restricted stock units.

	/s/ Christian Vasquez, as Attorney-in-Fact for Richard A. Waldron	09/02/2025
	** 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 BioAtla (BCAB) insider Richard A. Waldron report on Form 4?

The filing reports a withholding disposition of 2,371 common shares on 08/31/2025 related to vested RSUs, at a price of $0.4555 per share.

Why were the 2,371 shares disposed of according to the Form 4?

The Form 4 states the shares were withheld by the issuer to satisfy income tax and withholding and remittance obligations in connection with vesting and net settlement of previously reported restricted stock units.

How many shares does Richard A. Waldron beneficially own after the transaction?

Following the withholding, the reporting person beneficially owns 338,521 shares (direct ownership).

What transaction code was used on the Form 4 and what does it indicate?

Transaction code F(1) is used; the filing explains this represents shares withheld to satisfy tax obligations related to RSU vesting (not an open-market sale).

Who signed the Form 4 for Richard A. Waldron and when?

The Form 4 was signed by Christian Vasquez, as Attorney-in-Fact, on 09/02/2025.