X0306 4 2022-03-29 0 0001884697 Starry Group Holdings, Inc. STRY 0001916518 Regan Brian Michael C/O STARRY GROUP HOLDINGS, INC. 38 CHAUNCY STREET, SUITE 200 BOSTON MA 02111 0 1 0 0 See Remarks Class A Common Stock 2022-03-29 4 A 0 55223 A 55223 D Stock Option (Right to Buy) 0.93 2022-03-29 4 A 0 14726 A 2027-03-27 Class A Common Stock 14726 14726 D Stock Option (Right to Buy) 0.93 2022-03-29 4 A 0 22089 A 2027-06-19 Class A Common Stock 22089 22089 D Stock Option (Right to Buy) 1.74 2022-03-29 4 A 0 55223 A 2028-04-02 Class A Common Stock 55223 55223 D Stock Option (Right to Buy) 1.74 2022-03-29 4 A 0 92039 A 2028-10-23 Class A Common Stock 92039 92039 D Stock Option (Right to Buy) 3.16 2022-03-29 4 A 0 92039 A 2030-10-05 Class A Common Stock 92039 92039 D Pursuant to the Agreement and Plan of Merger, dated as of October 6, 2021 (as the same has been or may be amended, modified, supplemented or waived from time to time, the "Merger Agreement") by and among FirstMark Horizon Acquisition Corp., Sirius Merger Sub, Inc., Starry, Inc. ("Starry"), and the Starry Group Holdings, Inc. (the "Issuer"), each outstanding Starry equity award was converted into a corresponding equity award of the Issuer, on the same terms and conditions as were applicable to the Starry equity award, based on the applicable exchange ratio (determined in accordance with the Merger Agreement). Consists of 55,223 restricted stock units (the "RSUs"), that are subject to both a time-based vesting requirement and a liquidity event vesting requirement. The liquidity event will be satisfied on the first to occur of (i) the day following the expiration of the lock-up period set forth in the Issuer's bylaws and (ii) a sale event with respect to the Issuer. The time-based vesting occurs in 16 substantially equal quarterly installments commencing on May 29, 2021, subject to the Reporting Person's continued service through the applicable vesting date. The RSUs will be settled in shares of Class A Common Stock upon vesting. This option is fully vested and exercisable. The option vested and became exercisable as to 25% of the underlying shares on December 3, 2019, and the remainder has vested and will continue to vest in 36 substantially equal monthly installments thereafter. The option vested and became exercisable as to 25% of the underlying shares on October 6, 2021, and the remainder has vested and will continue to vest in 36 substantially equal monthly installments thereafter. Executive Vice President, Strategy and Chief of Staff /s/ William Lundregan, attorney-in-fact 2022-03-31