AMPL · Amplitude, Inc.

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 the reporting person, (c) the date that is six months following the date on which the reporting person is no longer an employee or director of the Issuer (unless such reporting person 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).

This transaction involved a gift of securities by the trust to the reporting person's spouse. This is not a market transaction, thus no price has been reported. No value was received for the gifted shares.

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 the reporting person, (c) the date that is six months following the date on which the reporting person is no longer an employee or director of the Issuer (unless such reporting person 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).

This transaction involved a gift of securities by the trust to the reporting person's spouse. This is not a market transaction, thus no price has been reported. No value was received for the gifted shares.

Securities held by a trust over which the reporting person exercises voting and dispositive control.

Represents restricted stock units ("RSUs") that were granted pursuant to the Issuer's Non-Employee Director Compensation Program (the"Program") in lieu of retainer fees. Each RSU represents a right to receive one share of Class A Common Stock. Issuance of the RSU shares has been deferred pursuant to the terms of the Program.

Includes 50,789 RSUs.

Represents restricted stock units ("RSUs") that were granted pursuant to the Issuer's Non-Employee Director Compensation Program (the"Program") in lieu of retainer fees. Each RSU represents a right to receive one share of Class A Common Stock. Issuance of the RSU shares has been deferred pursuant to the terms of the Program.

Includes 28,194 RSUs.

Shares sold to satisfy tax obligations in connection with the vesting of restricted stock units ("RSUs"), pursuant to a 10b5-1 trading plan adopted by the Reporting Person on December 11, 2025.

This transaction was executed in multiple trades in prices ranging from $6.5800 to $6.9400, inclusive. The price reported in Column 4 above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote.

Includes 24,857 RSUs.

Represents restricted stock units ("RSUs") that were granted pursuant to the Issuer's Non-Employee Director Compensation Program (the "Program"). Each RSU represents a right to receive one share of Class A Common Stock. The RSUs will vest in full on the earlier of (i) June 9, 2027 or (ii) immediately before the Issuer's 2027 annual meeting of stockholders, subject to the Reporting Person's continued service on the Board through such vesting date.

Includes 24,857 RSUs.

Represents restricted stock units ("RSUs") that were granted pursuant to the Issuer's Non-Employee Director Compensation Program. Each RSU represents a right to receive one share of Class A Common Stock. The RSUs will vest in full on the earlier of (i) June 9, 2027 or (ii) immediately before the Issuer's 2027 annual meeting of stockholders, subject to the Reporting Person's continued service on the Board through such vesting date.

Includes 24,857 RSUs.

Represents restricted stock units ("RSUs") that were granted pursuant to the Issuer's Non-Employee Director Compensation Program (the "Program"). Each RSU represents a right to receive one share of Class A Common Stock. The RSUs will vest in full on the earlier of (i) June 9, 2027 or (ii) immediately before the Issuer's 2027 annual meeting of stockholders, subject to the Reporting Person's continued service on the Board through such vesting date.

Includes (i) 13,729 shares of Class A Common Stock received in a pro rata in-kind distribution exempt from reporting pursuant to Rule 16a-9, and (ii) 58,657 RSUs.

Represents restricted stock units ("RSUs") that were granted pursuant to the Issuer's Non-Employee Director Compensation Program (the "Program"). Each RSU represents a right to receive one share of Class A Common Stock. The RSUs will vest in full on the earlier of (i) June 9, 2027 or (ii) immediately before the Issuer's 2027 annual meeting of stockholders, subject to the Reporting Person's continued service on the Board through such vesting date.

Includes 36,214 RSUs.

Represents restricted stock units ("RSUs") that were granted pursuant to the Issuer's Non-Employee Director Compensation Program (the "Program"). Each RSU represents a right to receive one share of Class A Common Stock. Vesting of the RSUs has been deferred pursuant to the terms of the Program.

Includes 26,535 RSUs.

The sales reported were effected pursuant to a 10b5-1 trading plan adopted by the Reporting Person on November 26, 2025.

This Form 4/A is being filed solely to correct the number of shares reported as sold on June 1, 2026 and the total number of shares owned following the transaction. Due to a broker administrative error, 585 fewer shares were sold than were required pursuant to the Reporting Person's Rule 10b5-1 trading plan. The error was corrected through the broker's error account, with the broker crediting the Reporting Person for the additional 585 shares at the applicable June 1, 2026 sale price and absorbing the cost of the correction. No additional open-market sale was effected in connection with the correction.

This transaction was executed in multiple trades at prices ranging from $8.0000 to $8.0600. The price reported in Column 4 above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote.

Includes 880,520 restricted stock units.

Represents shares of the Issuer's Class A Common Stock withheld by the Issuer solely to satisfy tax withholding obligations in connection with the net issuance of shares of the Issuer's Class A Common Stock delivered to the reporting person on May 15, 2026, from the vesting of restricted stock units ("RSUs"), and does not represent a sale by the Reporting Person.

Includes 958,054 RSUs.

Includes 2,500 shares acquired under the Issuer's employee stock purchase plan on May 14, 2026.

Represents shares of the Issuer's Class A Common Stock withheld by the Issuer solely to satisfy tax withholding obligations in connection with the net issuance of shares of the Issuer's Class A Common Stock delivered to the reporting person on May 15, 2026, from the vesting of restricted stock units ("RSUs"), and does not represent a sale by the Reporting Person.

Includes 1,212,859 RSUs.

Represents shares of the Issuer's Class A Common Stock withheld by the Issuer solely to satisfy tax withholding obligations in connection with the net issuance of shares of the Issuer's Class A Common Stock delivered to the reporting person on May 15, 2026, from the vesting of restricted stock units ("RSUs"), and does not represent a sale by the Reporting Person.

Includes 880,520 RSUs.

Represents shares of the Issuer's Class A Common Stock withheld by the Issuer solely to satisfy tax withholding obligations in connection with the net issuance of shares of the Issuer's Class A Common Stock delivered to the reporting person on May 15, 2026, from the vesting of restricted stock units ("RSUs"), and does not represent a sale by the Reporting Person.

Includes 1,471,366 RSUs.

Includes 2,330 shares acquired under the Issuer's employee stock purchase plan on May 14, 2026.

The sales reported were effected pursuant to a 10b5-1 trading plan adopted by the Reporting Person on November 26, 2025.

This transaction was executed in multiple trades at prices ranging from $8.0000 to $8.2200. The price reported in Column 4 above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote.

Includes 986,412 restricted stock units.

Each restricted stock unit ("RSU") represents a right to receive one share of the Issuer's Class A Common Stock. The RSUs vest in twelve substantially equal quarterly installments beginning on May 15, 2026, subject to the continued service of the Reporting Person through each vesting date.

Includes 1,323,119 RSUs.

Each restricted stock unit ("RSU") represents a right to receive one share of the Issuer's Class A Common Stock. The RSUs vest in twelve substantially equal quarterly installments beginning on May 15, 2026, subject to the continued service of the reporting person through each vesting date.

Includes 1,101,159 RSUs.

Each restricted stock unit ("RSU") represents a right to receive one share of the Issuer's Class A Common Stock. The RSUs vest in four substantially equal quarterly installments beginning on May 15, 2026, subject to the continued service of the reporting person through each vesting date.

Includes 726,441 restricted stock units.

Each restricted stock unit ("RSU") represents a right to receive one share of the Issuer's Class A Common Stock. The RSUs vest in twelve substantially equal quarterly installments beginning on May 15, 2026, subject to the continued service of the reporting person through each vesting date.

Includes 986,412 RSUs.

The Form 4s filed by the reporting person on March 9, 2026 and March 10, 2026 understated the reporting person's beneficial ownership by 63,262 shares. The correct number of shares beneficially owned following the transaction on April 15, 2026 is reflected herein.

Each RSU represents a right to receive one share of the Issuer's Class A Common Stock. The RSUs vest in twelve substantially equal quarterly installments beginning on May 15, 2026, subject to the continued service of the reporting person through each vesting date.

Includes 1,701,371 RSUs.

Represents restricted stock units ("RSUs") that were granted pursuant to the Issuer's Non-Employee Director Compensation Program (the"Program") in lieu of retainer fees. Each RSU represents a right to receive one share of Class A Common Stock. Issuance of the RSU shares has been deferred pursuant to the terms of the Program.

Includes 16,584 RSUs.

Represents restricted stock units ("RSUs") that were granted pursuant to the Issuer's Non-Employee Director Compensation Program (the"Program") in lieu of retainer fees. Each RSU represents a right to receive one share of Class A Common Stock. Issuance of the RSU shares has been deferred pursuant to the terms of the Program.

Includes 49,268 RSUs.

The sales reported were effected pursuant to a 10b5-1 trading plan adopted by the reporting person on November 26, 2025.

This transaction was executed in multiple trades at prices ranging from $8.00 to $8.04. The price reported in Column 4 above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote.

Includes 568,585 restricted stock units.

The sales reported were effected pursuant to a 10b5-1 trading plan adopted by the reporting person on November 26, 2025.

This transaction was executed in multiple trades in prices ranging from $8.00 to $8.02, inclusive. The price reported in Column 4 above reflects the weighted average sale price. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote.

Includes 568,585 restricted stock units.

Represents shares of the Issuer's Class A Common Stock withheld by the Issuer solely to satisfy tax withholding obligations in connection with the net issuance of shares of the Issuer's Class A Common Stock delivered to the reporting person on February 15, 2026, from the vesting of restricted stock units ("RSUs"), and does not represent a sale by the reporting person.

Includes 669,405 RSUs.

Represents shares of the Issuer's Class A Common Stock withheld by the Issuer solely to satisfy tax withholding obligations in connection with the net issuance of shares of the Issuer's Class A Common Stock delivered to the reporting person on February 15, 2026, from the vesting of restricted stock units ("RSUs"), and does not represent a sale by the reporting person.

Includes 568,585 RSUs.

Represents shares of the Issuer's Class A Common Stock withheld by the Issuer solely to satisfy tax withholding obligations in connection with the net issuance of shares of the Issuer's Class A Common Stock delivered to the reporting person on February 15, 2026, from the vesting of restricted stock units ("RSUs"), and does not represent a sale by the reporting person.

Includes 960,020 RSUs.

Represents restricted stock units ("RSUs") that were granted pursuant to the Issuer's Non-Employee Director Compensation Program (the"Program") in lieu of retainer fees. Each RSU represents a right to receive one share of Class A Common Stock. Issuance of the RSU shares has been deferred pursuant to the terms of the Program.

Includes 47,730 RSUs.

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.

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 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.

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 on March 12, 2025.

This transaction was executed in multiple trades at prices ranging from $10.7200 to $11.1900. 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.

Includes 14,906 RSUs.

The option is early exercisable. 1/48th of the shares subject to the option vest on each monthly anniversary measured from December 10, 2020 (the "Vesting Commencement Date"), such that 100% of the shares subject to the option will be fully vested on the fourth anniversary of the Vesting Commencement Date.

The sales reported were effected pursuant to a 10b5-1 trading plan adopted by the reporting person on March 12, 2025.

This transaction was executed in multiple trades at prices ranging from $9.5000 to $10.5800. 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.

The option is early exercisable. 1/48th of the shares subject to the option vest on each monthly anniversary measured from December 10, 2020 (the "Vesting Commencement Date"), such that 100% of the shares subject to the option will be fully vested on the fourth anniversary of the Vesting Commencement Date.

Represents shares of the Issuer's Class A Common Stock withheld by the Issuer solely to satisfy tax withholding obligations in connection with the net issuance of shares of the Issuer's Class A Common Stock delivered to the reporting person on November 15, 2025, from the vesting of restricted stock units ("RSUs"), and does not represent a sale by the reporting person.

Includes 639,658 RSUs.

Represents shares of the Issuer's Class A Common Stock withheld by the Issuer solely to satisfy tax withholding obligations in connection with the net issuance of shares of the Issuer's Class A Common Stock delivered to the reporting person on November 15, 2025, from the vesting of restricted stock units ("RSUs"), and does not represent a sale by the reporting person.

Includes 1,140,440 RSUs.

Represents shares of the Issuer's Class A Common Stock withheld by the Issuer solely to satisfy tax withholding obligations in connection with the net issuance of shares of the Issuer's Class A Common Stock delivered to the reporting person on November 15, 2025, from the vesting of restricted stock units ("RSUs"), and does not represent a sale by the reporting person.

Includes 1,140,440 RSUs.

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 $10.5500 to $11.2700. 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.

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).

This transaction was executed in multiple trades at prices ranging from $9.90 to $10.07, inclusive. The price reported in Column 4 above reflects the weighted average price. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares purchased at each respective price within the range set forth in this footnote.

Includes 883,657 RSUs.

Includes 2,500 shares acquired under the Issuer's employee stock purchase plan on May 14, 2025.

The option is early exercisable. 1/48th of the shares subject to the option vest on each monthly anniversary measured from December 10, 2020 (the"Vesting Commencement Date"), such that 100% of the shares subject to the option will be fully vested on the fourth anniversary of the Vesting Commencement Date.