X0609 4 2026-09-28 0 0001517413 Fastly, Inc. FSLY 0001769490 Bergman Artur false C/O FASTLY, INC. 475 BRANNAN STREET, SUITE 300 SAN FRANCISCO CA 94107 1 1 0 0 Chief Technology Officer 1 Class A Common Stock 2026-09-28 4 S 0 32878 24.75 D 1105480 I See Footnote. Class A Common Stock 2026-09-28 4 S 0 200 25.225 D 1105280 I See Footnote. Class A Common Stock 2026-09-29 4 S 0 3961 25.26 D 1101319 I See Footnote. Class A Common Stock 1896249 D Class A Common Stock 840005 I See Footnote Class A Common Stock 109686 I See Footnote Class A Common Stock 156521 I See Footnote Class A Common Stock 588671 I See Footnote Class A Common Stock 254808 I See Footnote The sale was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on June 4, 2026. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $24.22 to $25.20, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (2), (4) and (5) to this Form 4. The shares are held by The Per Artur Bergman Revocable Trust, of which the reporting person is settlor, sole trustee, and sole beneficiary. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.22 to $25.23, inclusive. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $25.00 to $25.52, inclusive. The shares are held by The Artur Bergman Remainder Trust One DTD 5/2/2019, of which the reporting person is the investment advisor. The shares are held by The Artur Bergman Remainder Trust Three DTD 5/2/2019, of which the reporting person is the investment advisor. The shares are held by The PAB 2021 Remainder Trust, of which the reporting person is the investment advisor. The shares are held by The Per Artur Bergman Grantor Retained Annuity Trust No. 4, of which the reporting person is trustee. The shares are held by The Per Artur Bergman Grantor Retained Annuity Trust No. 5, of which the reporting person is trustee. /s/ Tara Seracka, Attorney-in-Fact 2026-09-30