X0306 4 2021-10-25 0 0001818331 Sema4 Holdings Corp. SMFR 0001873883 Coffin James C/O SEMA4 HOLDINGS CORP. 333 LUDLOW ST, NORTH TOWER, 8TH FL. STAMFORD CT 06902 0 1 0 0 President and COO Class A Common Stock 2021-10-25 4 M 0 22517 A 22517 D Class A Common Stock 2021-10-25 4 S 0 5752 7.54 D 16765 D Restricted Stock Unit 2021-10-25 4 M 0 22517 0.00 D Class A Common Stock 22517 337768 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. 6.25% vest in quarterly installments over the four-year period commencing on July 25, 2021 until fully vested, subject to the Reporting Person's continued service to the Issuer on each vesting date. /s/ Daniel Clark, Attorney-in-Fact 2021-11-02