X0508 4 2023-11-15 0001042074 CymaBay Therapeutics, Inc. CBAY 0001333277 Quinlan Paul T C/O CYMABAY THERAPEUTICS, INC. 7575 GATEWAY BLVD., SUITE 110 NEWARK CA 94560 0 1 0 0 General Counsel 0 Common Stock 2023-11-15 4 M 0 5000 2.94 A 5000 D Common Stock 2023-11-15 4 S 0 5000 17.3778 D 0 D Employee Stock Option (right to buy) 2.94 2023-11-15 4 M 0 5000 0 D 2032-01-24 Common Stock 5000 117000 D The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan entered into on February 14, 2023. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $17.00 to $17.55, inclusive. The reporting person undertakes to provide to CymaBay Therapeutics, Inc., any security holder of CymaBay Therapeutics, Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. The option grant vests as to 1/48 of the underlying shares monthly from January 1, 2022. /s/ Paul Quinlan 2023-11-15