X0609 4 2026-08-12 0 0001447669 TWILIO INC TWLO 0002018024 Stafman Andrew false 250 WEST 55TH STREET, FLOOR 34 NEW YORK NY 10019 1 0 0 0 0001658919 Ferguson Scott D. false 250 WEST 55TH STREET, 34TH FLOOR NEW YORK NY 10019 0 0 0 1 See Footnotes 0001582090 Sachem Head Capital Management LP false 250 WEST 55TH STREET, 34TH FLOOR NEW YORK NY 10019 0 0 0 1 See Footnotes 0001658906 Uncas GP LLC false 250 WEST 55TH STREET, FLOOR 34 NEW YORK NY 10019 0 0 0 1 See Footnotes 0001658917 Sachem Head GP LLC false 250 WEST 55TH STREET, FLOOR 34 NEW YORK NY 10019 0 0 0 1 See Footnotes 0 Class A Common Stock 2026-08-12 4 S 0 500000 247.08 D 120000 I See footnotes Class A Common Stock 13492 D In addition to Andrew J. Stafman, this Form 4 is being filed jointly by Sachem Head Capital Management LP ("Sachem Head"), Uncas GP LLC ("SH Management"), Sachem Head GP LLC ("Sachem Head GP"), and Scott D. Ferguson, a citizen of the United States (Mr. Ferguson and, together with Sachem Head, SH Management, Sachem GP, and Mr. Stafman, the "Reporting Persons"). Each of the Reporting Persons has the same business address as Mr. Stafman and may be deemed to be the beneficial owner of certain of the securities reported on this Form 4 (the "Subject Securities") for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended. Each of the Reporting Persons disclaims any beneficial ownership of any of the Subject Securities, except to the extent of any pecuniary interest therein. Includes securities directly owned by Sachem Head LP ("SH") and Sachem Head Master LP ("SHM" and, together with SH, the "Sachem Head Funds"). Each of Sachem Head, as the investment adviser to the Sachem Head Funds, SH Management, as the sole general partner of Sachem Head, and Scott D. Ferguson, as the managing partner of Sachem Head, may be deemed to beneficially own the securities directly owned by the Sachem Head Funds. As the general partner of SH and SHM, Sachem Head GP may be deemed to beneficially own the securities directly owned by SH and SHM. The principal business of Sachem Head is to serve as investment advisor to certain affiliated funds, including the Sachem Head Funds. The principal business of SH Management is to serve as the sole general partner of Sachem Head. The principal business of Sachem Head GP is to serve as the general partner of certain affiliated funds, including SH and SHM. The principal occupation of Scott D. Ferguson is to serve as the managing partner of Sachem Head and the managing member of SH Management and Sachem Head GP. Andrew J. Stafman is a partner at Sachem Head and also serves on the board of directors of the Issuer. As a result, the Reporting Persons other than Mr. Stafman may be deemed directors of the Issuer by deputization. Pursuant to an arrangement between Andrew J. Stafman and Sachem Head, upon receipt of the Subject Securities, Andrew J. Stafman granted all right, title, interest, claims, and any other ownership interests in such Subject Securities to Sachem Head for no consideration. /s/ Michael D. Adamski, as Attorney-in-Fact for Andrew J. Stafman 2026-08-12 /s/ Michael D. Adamski, as Attorney-in-Fact for Scott D. Ferguson 2026-08-12 /s/ Michael D. Adamski, as General Counsel of Sachem Head Capital Management LP 2026-08-12 /s/ Michael D. Adamski, as General Counsel of Uncas GP LLC 2026-08-12 /s/ Michael D. Adamski, as General Counsel of Sachem Head GP LLC 2026-08-12