X0306 4 2021-10-25 0 0001818331 Sema4 Holdings Corp. SMFR 0001873463 Ro Isaac C/O SEMA4 HOLDINGS CORP. 333 LUDLOW ST, NORTH TOWER, 8TH FL. STAMFORD CT 06902 0 1 0 0 Chief Financial Officer Class A Common Stock 2021-10-25 4 M 0 125000 A 125000 D Class A Common Stock 2021-10-25 4 S 0 40848 7.54 D 84152 D Restricted Stock Unit 2021-10-25 4 M 0 125000 0.00 D Class A Common Stock 125000 875000 D Each restricted stock unit ("RSU") represents a contingent right to receive 1 share of the Issuer's Class A Common Stock upon settlement for no consideration. The sale reported on this Form 4 represents shares sold by the Reporting Person to cover tax withholding obligations in connection with the vesting and settlement of RSUs. The sale was to satisfy tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary transaction by the Reporting Person. 1/8th of the total shares vested on October 25, 2021, 1/16th of the total shares vest on November 8, 2021, and thereafter vests as to 1/16th of the total shares underlying the award in quarterly installments until fully vested on February 8, 2025, subject to the Reporting Person's continued service to the Issuer on each vesting date. /s/ Daniel Clark, Attorney-in-Fact 2021-11-02