QUBT · Quantum Computing Inc.

This Form 4/A is being filed solely to correct the exercise price of the warrants to purchase 584,897 shares of common stock of the Registrant, which were acquired in connection with the acquisition of QPhoton, Inc. by Quantum Computing Inc. in June 2022 and exercised on August 20, 2026. The correct exercise price of the warrants of $0.0001 per share was previously reported in the Form 3 filed by the reporting person on July 27, 2022.

This Form 4/A is being filed solely to correct the exercise price of the warrants to purchase 584,897 shares of common stock of the Registrant, which were acquired in connection with the acquisition of QPhoton, Inc. by Quantum Computing Inc. in June 2022 and exercised on August 20, 2026. The correct exercise price of the warrants of $0.0001 per share was previously reported in the Form 3 filed by the reporting person on July 27, 2022.

On May 28, 2026, the Reporting Person was granted 24,774 restricted stock units ("RSUs"). Each RSU represents the right to receive one share of the Company's common stock upon vesting. The RSUs will vest as follows: 1/3 of the RSUs will vest on May 28, 2027, 1/3 of the RSUs will vest on May 28, 2028 and 1/3 of the RSUs will vest on May 28, 2029, in each case subject to the Reporting Person's continuous service through each applicable vesting date.

On May 28, 2026, the Reporting Person was granted stock options to purchase 23,588 shares of the Company's common stock at an exercise price of $12.24 per share, which was the closing price on the Nasdaq Stock Market on the grant date. The options have a ten-year term and will vest as follows: 1/3 of the options will vest on May 28, 2027, 1/3 of the options will vest on May 28, 2028 and 1/3 of the options will vest on May 28, 2029, in each case subject to the Reporting Person's continuous service through each applicable vesting date.

On May 28, 2026, the Reporting Person was granted 24,774 restricted stock units ("RSUs"). Each RSU represents the right to receive one share of the Company's common stock upon vesting. The RSUs will vest as follows: 1/3 of the RSUs will vest on May 28, 2027, 1/3 of the RSUs will vest on May 28, 2028 and 1/3 of the RSUs will vest on May 28, 2029, in each case subject to the Reporting Person's continuous service through each applicable vesting date.

On May 28, 2026, the Reporting Person was granted stock options to purchase 9,979 shares of the Company's common stock at an exercise price of $12.24 per share, which was the closing price on the Nasdaq Stock Market on the grant date. The options have a ten-year term and will vest as follows: 1/3 of the options will vest on May 28, 2027, 1/3 of the options will vest on May 28, 2028 and 1/3 of the options will vest on May 28, 2029, in each case subject to the Reporting Person's continuous service through each applicable vesting date.

On May 28, 2026, the Reporting Person was granted stock options to purchase 9,979 shares of the Company's common stock at an exercise price of $12.24 per share, which was the closing price on the Nasdaq Stock Market on the grant date. The options have a ten-year term and will vest as follows: 1/3 of the options will vest on May 28, 2027, 1/3 of the options will vest on May 28, 2028 and 1/3 of the options will vest on May 28, 2029, in each case subject to the Reporting Person's continuous service through each applicable vesting date.

On May 28, 2026, the Reporting Person was granted 58,558 restricted stock units ("RSUs"). Each RSU represents the right to receive one share of the Company's common stock upon vesting. The RSUs will vest as follows: 1/3 of the RSUs will vest on May 28, 2027, 1/3 of the RSUs will vest on May 28, 2028 and 1/3 of the RSUs will vest on May 28, 2029, in each case subject to the Reporting Person's continuous service through each applicable vesting date.

Represents restricted stock units (RSUs) granted to the Reporting Person under the Quantum Computing Inc. 2022 Equity and Incentive Plan. Such RSUs will vest as follows: 1/4 of the RSUs will vest immediately upon grant, 1/4 of the RSUs will vest on June 30, 2026, 1/4 of the RSUs will vest on September 30, 2026 and 1/4 of the RSUs will vest on December 31, 2026, in each case subject to the Reporting Person's continuous service through each applicable vesting date.

Represents restricted stock units (RSUs) granted to the Reporting Person under the Quantum Computing Inc. 2022 Equity and Incentive Plan. Such RSUs will vest as follows: 1/4 of the RSUs will vest immediately upon grant, 1/4 of the RSUs will vest on June 30, 2026, 1/4 of the RSUs will vest on September 30, 2026 and 1/4 of the RSUs will vest on December 31, 2026, in each case subject to the Reporting Person's continuous service through each applicable vesting date.

Represents restricted stock units (RSUs) granted to the Reporting Person under the Quantum Computing Inc. 2022 Equity and Incentive Plan. Such RSUs will vest as follows: 1/4 of the RSUs will vest immediately upon grant, 1/4 of the RSUs will vest on June 30, 2026, 1/4 of the RSUs will vest on September 30, 2026 and 1/4 of the RSUs will vest on December 31, 2026, in each case subject to the Reporting Person's continuous service through each applicable vesting date.

Represents restricted stock units (RSUs) granted to the Reporting Person under the Quantum Computing Inc. 2022 Equity and Incentive Plan. Such RSUs will vest as follows: 1/4 of the RSUs will vest immediately upon grant, 1/4 of the RSUs will vest on June 30, 2026, 1/4 of the RSUs will vest on September 30, 2026 and 1/4 of the RSUs will vest on December 31, 2026, in each case subject to the Reporting Person's continuous service through each applicable vesting date.

Represents restricted stock units (RSUs) granted to the Reporting Person under the Quantum Computing Inc. 2022 Equity and Incentive Plan. Such RSUs will vest as follows: 1/4 of the RSUs will vest immediately upon grant, 1/4 of the RSUs will vest on June 30, 2026, 1/4 of the RSUs will vest on September 30, 2026 and 1/4 of the RSUs will vest on December 31, 2026, in each case subject to the Reporting Person's continuous service through each applicable vesting date.

Sale of shares to cover the exercise price, withholding tax obligations and broker fees and commissions, pursuant to a broker assisted cashless exercise of vested stock options granted on April 26, 2021 under the 2019 Quantum Computing Inc. Equity and Incentive Plan.

The price reported in Column 4 is a weighted-average price. These shares were sold in multiple transactions at prices ranging from $7.8500 to $7.8550 on March 10, 2026 and March 11, 2026. The Reporting Person undertakes to provide the Registrant, any securityholder of the Registrant, or the Staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

The stock option was granted on April 26, 2021 (the "Date of Grant"), and had a vesting commencement date of April 26, 2021. The options vested as follows: (i) 150,000 Options vested immediately upon grant (ii) 83,333 Options vested on the 12-month anniversary of the Date of Grant (iii), 83,333 Options vested on the 24-month anniversary of the Date of Grant and (iv) 83,334 Options vested on the 36-month anniversary of the Date of Grant.

Sale of shares to cover the exercise price, withholding tax obligations and broker fees and commissions, pursuant to a broker assisted cashless exercise of vested stock options granted on April 26, 2021 under the 2019 Quantum Computing Inc. Equity and Incentive Plan.

The price reported in Column 4 is a weighted-average price. These shares were sold in multiple transactions at prices ranging from $7.8500 to $7.8550 on March 10, 2026 and March 11, 2026. The Reporting Person undertakes to provide the Registrant, any securityholder of the Registrant, or the Staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

2,860 shares were sold to cover taxes at a weighted average price of $11.85.

13,550 restricted stock awards previously granted to the Reporting Person vested on December 31, 2025. The awards were granted on October 3, 2024, with half vesting on December 31, 2024, and the remaining half vesting on December 31, 2025.

Fagenson Fixed Income Partners, LLC, for which the reporting person serves as managing member, sold a total of 100,000 shares of the Issuer's common stock from September 9 to September 12, 2025.

Fagenson Fixed Income Partners, LLC, for which the reporting person serves as managing member, sold a total of 100,000 shares of the Issuer's common stock from September 9 to September 12, 2025.

Represents a bona fide gift of 400,000 shares of common stock by the Reporting Person to a charitable trust.

Fagenson Fixed Income Partners, LLC, for which the reporting person serves as managing member, sold a total of 100,000 shares of the Issuer's common stock from September 9 to September 12, 2025.

Fagenson Fixed Income Partners, LLC, for which the reporting person serves as managing member, sold a total of 100,000 shares of the Issuer's common stock from September 9 to September 12, 2025.

Fagenson Fixed Income Partners, LLC, for which the reporting person serves as managing member, sold a total of 100,000 shares of the Issuer's common stock from September 9 to September 12, 2025.

These shares were acquired by the Reporting Person on August 18, 2025 by exercising the Stock Options (defined below) to purchase 40,000 shares of the Company's common stock, par value $0.0001 per share ("Common Stock"), all of which were vested, using a "net exercise" method at a cashless exercise price of $15.84 per share, resulting in the issuance of 37,474 shares of Common Stock.

These shares were acquired by the Reporting Person on August 18, 2025 by exercising the Stock Options (defined below) to purchase 40,000 shares of the Company's common stock, par value $0.0001 per share ("Common Stock"), all of which were vested, using a "net exercise" method at a cashless exercise price of $15.84 per share, resulting in the issuance of 37,474 shares of Common Stock.

The non-qualified stock options (the "Stock Options") were granted to the Reporting Person on May 10, 2024 pursuant to the Quantum Computing Inc. 2022 Equity and Incentive Plan and according to the terms of the director agreement by and between the Reporting Person and the Issuer, at an exercise price of $1.00 and fully vested on December 31, 2024.

These shares were acquired by the Reporting Person on August 18, 2025 by exercising the Stock Options (defined below), all of which were vested, using a "net exercise" method at a cashless exercise price of $15.841 per share, resulting in the issuance of 17,175 shares of the Company's common stock, par value $0.0001 per share ("Common Stock").

These shares were acquired by the Reporting Person on August 18, 2025 by exercising the Stock Options (defined below), all of which were vested, using a "net exercise" method at a cashless exercise price of $15.841 per share, resulting in the issuance of 17,175 shares of the Company's common stock, par value $0.0001 per share ("Common Stock").

Pursuant to a Quantum Computing Inc. Non-Qualified Stock Option Agreement (Employee) by and between the Reporting Person and the Issuer, dated October 4, 2024 (as amended on March 21, 2025) the reporting person was granted non-qualified stock options (the "Stock Options") to purchase up to 55,000 shares of the Common Stock, at an exercise price of $1.00. The Stock Options vest annually over three years from July 22, 2024, subject to continued service, and are exercisable until October 4, 2029.

These Options were granted to the Reporting Person on July 11, 2025, pursuant to his employment agreement and the Quantum Computing Inc. 2022 Equity and Incentive Plan. These options vest and become exercisable as follows: (i) 100,000 shall vest on the grant date or July 11, 2025; (ii) 100,000 shall vest on the one-year anniversary of the grant date or July 11, 2026; and (iii) 100,000 shall vest on the two-year anniversary of the grant date or July 11, 2027.

Nasdaq closing price on July 11, 2025.

On June 30, 2025, Dr. Yuping Huang exercised vested warrants (the "Warrants") to purchase 1,050,812 shares of common stock, which were acquired in the acquisition of QPhoton, Inc. by Quantum Computing Inc. in June 2022.

The total number of shares of common stock beneficially owned directly by Dr. Yuping Huang includes: (i) 21,236,906 shares of common stock issued to Dr. Huang as merger consideration in the acquisition of QPhoton, Inc. by Quantum Computing Inc. in June 2022, and (ii) 1,050,812 shares of common stock issued upon conversion of the Warrants, both of which are registered under the registration statement on Form S-3 (File No. 333-269063) and excludes: 314,350 shares of common stock issuable upon exercise of vested options to purchase shares of common stock.

These shares were acquired by the Reporting Person on June 13, 2025 by exercising 403,236 stock options to purchase shares of the Company's common stock, par value $0.0001 per share ("Common Stock"), all of which were vested, using a "net exercise" method at a cashless exercise price of $16.526 per share, resulting in the issuance of 351,152 shares of Common Stock.

These shares were acquired by the Reporting Person on June 13, 2025 by exercising 403,236 stock options to purchase shares of the Company's common stock, par value $0.0001 per share ("Common Stock"), all of which were vested, using a "net exercise" method at a cashless exercise price of $16.526 per share, resulting in the issuance of 351,152 shares of Common Stock.

The total number of shares of Common Stock beneficially owned directly by the Reporting Person does not include 164,814 shares of Common Stock issuable upon exercise of vested options to purchase shares of common stock.

These shares were acquired by the Reporting Person on June 13, 2025 by exercising 403,236 stock options to purchase shares of the Company's common stock, par value $0.0001 per share ("Common Stock"), all of which were vested, using a "net exercise" method at a cashless exercise price of $16.526 per share, resulting in the issuance of 351,152 shares of Common Stock.

These shares were acquired by the Reporting Person on June 13, 2025 by exercising 403,236 stock options to purchase shares of the Company's common stock, par value $0.0001 per share ("Common Stock"), all of which were vested, using a "net exercise" method at a cashless exercise price of $16.526 per share, resulting in the issuance of 351,152 shares of Common Stock.

The total number of shares of Common Stock beneficially owned directly by the Reporting Person does not include 164,814 shares of Common Stock issuable upon exercise of vested options to purchase shares of common stock.

These shares were acquired by the Reporting Person on June 13, 2025 by exercising 403,236 stock options to purchase shares of the Company's common stock, par value $0.0001 per share ("Common Stock"), all of which were vested, using a "net exercise" method at a cashless exercise price of $16.526 per share, resulting in the issuance of 351,152 shares of Common Stock.

The total number of shares of Common Stock beneficially owned directly by the Reporting Person does not include 164,814 shares of Common Stock issuable upon exercise of vested options to purchase shares of common stock.

These shares were acquired by the Reporting Person on June 13, 2025 by exercising 403,236 stock options to purchase shares of the Company's common stock, par value $0.0001 per share ("Common Stock"), all of which were vested, using a "net exercise" method at a cashless exercise price of $16.526 per share, resulting in the issuance of 351,152 shares of Common Stock.

The total number of shares of Common Stock beneficially owned directly by the Reporting Person does not include 164,814 shares of Common Stock issuable upon exercise of vested options to purchase shares of common stock.

These shares were acquired by the Reporting Person on June 13, 2025 by exercising 403,236 stock options to purchase shares of the Company's common stock, par value $0.0001 per share ("Common Stock"), all of which were vested, using a "net exercise" method at a cashless exercise price of $16.526 per share, resulting in the issuance of 351,152 shares of Common Stock.

The total number of shares of Common Stock beneficially owned directly by the Reporting Person does not include 164,814 shares of Common Stock issuable upon exercise of vested options to purchase shares of common stock.

These shares were acquired by the Reporting Person on June 13, 2025 by exercising 403,236 stock options to purchase shares of the Company's common stock, par value $0.0001 per share ("Common Stock"), all of which were vested, using a "net exercise" method at a cashless exercise price of $16.526 per share, resulting in the issuance of 351,152 shares of Common Stock.

These shares were acquired by the Reporting Person on June 13, 2025 by exercising 403,236 stock options to purchase shares of the Company's common stock, par value $0.0001 per share ("Common Stock"), all of which were vested, using a "net exercise" method at a cashless exercise price of $16.526 per share, resulting in the issuance of 351,152 shares of Common Stock.

These shares were acquired by the Reporting Person on June 13, 2025 by exercising 403,236 stock options to purchase shares of the Company's common stock, par value $0.0001 per share ("Common Stock"), all of which were vested, using a "net exercise" method at a cashless exercise price of $16.526 per share, resulting in the issuance of 351,152 shares of Common Stock.

The total number of shares of Common Stock beneficially owned directly by the Reporting Person does not include 164,814 shares of Common Stock issuable upon exercise of vested options to purchase shares of common stock.

The total number of shares of Common Stock beneficially owned directly by the Reporting Person does not include 727,876 shares of Common Stock issuable upon exercise of vested options to purchase shares of common stock.

The total number of shares of Common Stock beneficially owned directly by the Reporting Person does not include 727,876 shares of Common Stock issuable upon exercise of vested options to purchase shares of common stock.

The total number of shares of Common Stock beneficially owned directly by the Reporting Person does not include 400,000 shares of Common Stock issuable upon exercise of vested options to purchase shares of common stock.

The total number of shares of Common Stock beneficially owned directly by the Reporting Person does not include 727,876 shares of Common Stock issuable upon exercise of vested options to purchase shares of common stock.