X0508 4 2025-12-24 false 0001866692 Amplitude, Inc. AMPL 0001882913 Skates Spenser C/O AMPLITUDE, INC. 201 THIRD ST., SUITE 200 SAN FRANCISCO CA 94103 true true true false Chief Executive Officer true Class A Common Stock 2025-12-24 4 C false 42743.00 0.00 A 42743.00 I By Spouse Class A Common Stock 2025-12-24 4 S false 42743.00 12.0121 D 0.00 I By Spouse Class B Common Stock 2025-12-24 4 C false 42743.00 0.00 D Class A Common Stock 42743.00 567257.00 I By Spouse Class B Common Stock Class A Common Stock 5342146.00 5342146.00 D The Class B Common Stock is convertible at any time at the option of the holder into the Issuer's Class A Common Stock on a one-to-one basis. The Class B Common Stock will convert automatically into shares of the Issuer's Class A Common Stock on a one-to-one basis upon the earlier of (a) any transfer of the Class B Common Stock by the holder, whether or not for value, subject to certain exceptions, (b) the death or incapacity of Mr. Skates, (c) the date that is six months following the date on which Mr. Skates is no longer an employee or director of the Issuer (unless Mr. Skates has rejoined the Issuer during such six-month period) or (d) the date that is six months following the date on which none of the Issuer's founders is an employee or director of the Issuer (unless a founder has rejoined the Issuer during such six-month period). The sales reported were effected pursuant to a 10b5-1 trading plan adopted by the Reporting Person's spouse on August 8, 2025. This transaction was executed in multiple trades at prices ranging from $12.0000 to $12.0400. The price reported above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected. /s/ Elizabeth Fisher, as attorney in fact for Skates Spenser 2025-12-29