X0508 4 2023-12-31 0 0001826892 BioAtla, Inc. BCAB 0001725276 Williams Eddie C/O BIOATLA, INC. 11085 TORREYANA ROAD SAN DIEGO CA 92121 1 0 0 0 0 Common Stock 2023-12-31 4 A 0 4827 0.00 A 20200 D The reporting person has elected to receive fully vested shares of the Issuer's common stock in lieu of cash retainer fees payable for service on the Issuer's Board of Directors and any committees thereof. The number of shares issued represents the quotient of (A) the amount of such fees divided by (B) the Issuer's closing stock price on the date such fees would otherwise be paid, rounded up to the nearest whole share. /s/ Christian Vasquez, as Attorney-in-Fact for Edward Williams 2024-01-03