[Form 4] BioAtla, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Christian Vasquez, an officer at BioAtla, Inc. (BCAB) who serves as Chief Accounting Officer, Corporate Controller and Secretary, reported a transaction dated 08/31/2025 in which 1,566 shares of common stock were withheld by the issuer at a price of $0.4555 per share to satisfy income tax and withholding obligations related to the vesting and net settlement of previously reported restricted stock units. The filing shows 283,564 shares beneficially owned following the transaction and is signed by Mr. Vasquez on 09/02/2025. The filer explains this is not a sale but a withholding to cover taxes on vested RSUs.

Positive

• Disclosure clarity: The filing explicitly states the withholding was to satisfy taxes on vested RSUs, not an open-market sale.
• Continued insider ownership: Beneficial ownership remains 283,564 shares after the transaction, indicating ongoing alignment with shareholders.
• Timely filing: The form is signed and dated shortly after the transaction (signed 09/02/2025 for an 08/31/2025 transaction).

Negative

• None.

Insights

Financial Analyst

TL;DR Routine tax-withholding on vested equity; no sale and limited market impact.

This Form 4 discloses a small withholding of 1,566 shares to satisfy tax obligations from vested restricted stock units. Because the transaction is labeled F(1) and explicitly described as issuer withholding rather than an open-market sale, it does not represent active disposition pressure on the stock. Post-transaction beneficial ownership remains 283,564 shares, indicating continued insider alignment with shareholders. The dollar value of the withheld shares at the reported price is modest relative to typical institutional trading volumes.

Corporate Governance Expert

TL;DR Standard administrative equity settlement; transparency is appropriate and timely.

The reporting clarifies the nature of the change in beneficial ownership as a tax-withholding event tied to vested RSUs, which is a common administrative practice. The filer included officer titles in remarks, improving disclosure clarity regarding the reporting person's roles. The Form 4 was signed promptly after the transaction date, supporting compliance with Section 16 reporting expectations. No governance red flags or unexplained dispositions are evident from this filing.

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

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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^*

Vasquez Christian

(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)
	See Remarks

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)		1,566	D	$0.4555	283,564	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.

Remarks:

Chief Accounting Officer, Corporate Controller and Secretary.

	/s/ Christian Vasquez	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 Christian Vasquez report on Form 4 for BCAB?

He reported that 1,566 common shares were withheld by the issuer on 08/31/2025 to satisfy income tax and withholding obligations related to vested restricted stock units.

Did Mr. Vasquez sell shares of BCAB in this filing?

No. The filing states this was not a sale but shares withheld by the issuer to cover taxes from vesting and net settlement of previously reported RSUs.

How many BCAB shares does Mr. Vasquez beneficially own after the transaction?

The filing reports 283,564 shares beneficially owned following the reported transaction.

What does transaction code F(1) indicate on this Form 4?

In this filing, F(1) corresponds to shares withheld by the issuer to satisfy tax withholding on vested restricted stock units, as explained in the form's explanation section.

What are Mr. Vasquez's roles at BioAtla listed in the filing?

The remarks identify him as Chief Accounting Officer, Corporate Controller and Secretary.