X0306 4 2022-10-15 0 0001818331 Sema4 Holdings Corp. SMFR 0001585017 Ryan Jason C/O SEMA4 HOLDINGS CORP. 333 LUDLOW ST, NORTH TOWER, 8TH FL. STAMFORD CT 06902 1 1 0 0 Executive Chairman Class A Common Stock 2022-10-15 4 M 0 4278 A 17114 D Class A Common Stock 2022-10-17 4 S 0 1281 0.8598 D 15833 D Restricted Stock Unit 2022-10-15 4 M 0 4278 0.00 D Class A Common Stock 4278 8558 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. The RSUs will vest in equal annual installments over the three-year period following the grant date of October 15, 2021, subject to the Reporting Person continuing to provide services to the Issuer through each vesting date. /s/ Bridget Brown, Attorney-in-Fact 2022-10-18