PRAX · Praxis Precision Medicines, Inc.

This transaction represents a bona fide gift of common stock to the Souza 2026 Trust.

This transaction represents a bona fide gift of common stock to the Souza 2026 Trust.

This option was fully vested as of May 23, 2025.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted on March 25, 2026.

The price reported is a weighted average price. The securities were sold in multiple transactions at per share prices ranging from $307.900 to $308.870. The Reporting Person undertakes to provide upon request from the SEC staff, the Issuer, or any shareholder of the Issuer, full information regarding the number of securities sold at each separate price within the range set forth in this footnote.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted on March 25, 2026.

The price reported is a weighted average price. The securities were sold in multiple transactions at per share prices ranging from $315.590 to $316.010. The Reporting Person undertakes to provide upon request from the SEC staff, the Issuer, or any shareholder of the Issuer, full information regarding the number of securities sold at each separate price within the range set forth in this footnote.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted on March 25, 2026.

The price reported is a weighted average price. The securities were sold in multiple transactions at per share prices ranging from $306.365 to $307.180. The Reporting Person undertakes to provide upon request from the SEC staff, the Issuer, or any shareholder of the Issuer, full information regarding the number of securities sold at each separate price within the range set forth in this footnote.

This option was fully vested as of June 5, 2025.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted on March 25, 2026.

The price reported is a weighted average price. The securities were sold in multiple transactions at per share prices ranging from $305.000 to $305.830. The Reporting Person undertakes to provide upon request from the SEC staff, the Issuer, or any shareholder of the Issuer, full information regarding the number of securities sold at each separate price within the range set forth in this footnote.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted on March 25, 2026.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted on March 25, 2026.

The price reported is a weighted average price. The securities were sold in multiple transactions at per share prices ranging from $311.340 to $312.320. The Reporting Person undertakes to provide upon request from the SEC staff, the Issuer, or any shareholder of the Issuer, full information regarding the number of securities sold at each separate price within the range set forth in this footnote.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted on March 25, 2026.

The price reported is a weighted average price. The securities were sold in multiple transactions at per share prices ranging from $312.370 to $313.280. The Reporting Person undertakes to provide upon request from the SEC staff, the Issuer, or any shareholder of the Issuer, full information regarding the number of securities sold at each separate price within the range set forth in this footnote.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted on March 25, 2026.

The price reported is a weighted average price. The securities were sold in multiple transactions at per share prices ranging from $314.400 to $315.380. The Reporting Person undertakes to provide upon request from the SEC staff, the Issuer, or any shareholder of the Issuer, full information regarding the number of securities sold at each separate price within the range set forth in this footnote.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted on March 25, 2026.

The price reported is a weighted average price. The securities were sold in multiple transactions at per share prices ranging from $310.340 to $311.300. The Reporting Person undertakes to provide upon request from the SEC staff, the Issuer, or any shareholder of the Issuer, full information regarding the number of securities sold at each separate price within the range set forth in this footnote.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted on March 25, 2026.

The price reported is a weighted average price. The securities were sold in multiple transactions at per share prices ranging from $302.500 to $303.440. The Reporting Person undertakes to provide upon request from the SEC staff, the Issuer, or any shareholder of the Issuer, full information regarding the number of securities sold at each separate price within the range set forth in this footnote.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted on March 25, 2026.

The price reported is a weighted average price. The securities were sold in multiple transactions at per share prices ranging from $313.400 to $314.000. The Reporting Person undertakes to provide upon request from the SEC staff, the Issuer, or any shareholder of the Issuer, full information regarding the number of securities sold at each separate price within the range set forth in this footnote.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted on March 25, 2026.

The price reported is a weighted average price. The securities were sold in multiple transactions at per share prices ranging from $308.900 to $309.790. The Reporting Person undertakes to provide upon request from the SEC staff, the Issuer, or any shareholder of the Issuer, full information regarding the number of securities sold at each separate price within the range set forth in this footnote.

Ms. DeSimone was awarded 1,371 restricted stock units. Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock. The restricted stock units vest in a single annual installment on the earlier of (i) June 10, 2027 or (ii) the date of the Issuer's 2027 annual meeting of stockholders. The restricted stock units may be settled only by delivering shares of the Issuer's common stock, and thus, the grant is being reported in Table 1 as allowed per SEC guidance.

Dr. Cudkowicz was awarded 1,371 restricted stock units. Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock. The restricted stock units vest in a single annual installment on the earlier of (i) June 10, 2027 or (ii) the date of the Issuer's 2027 annual meeting of stockholders. The restricted stock units may be settled only by delivering shares of the Issuer's common stock, and thus, the grant is being reported in Table 1 as allowed per SEC guidance.

The shares subject to this option shall vest in twelve (12) equal monthly installments occurring on the 10th day of each month, with the first such installment occurring on July 10, 2026 and the final such installment occurring on the earlier of (i) June 10, 2027 or (ii) the date of the Issuer's 2027 annual meeting of stockholders.

The shares subject to this option shall vest in twelve (12) equal monthly installments occurring on the 10th day of each month, with the first such installment occurring on July 10, 2026 and the final such installment occurring on the earlier of (i) June 10, 2027 or (ii) the date of the Issuer's 2027 annual meeting of stockholders.

The shares subject to this option shall vest in twelve (12) equal monthly installments occurring on the 10th day of each month, with the first such installment occurring on July 10, 2026 and the final such installment occurring on the earlier of (i) June 10, 2027 or (ii) the date of the Issuer's 2027 annual meeting of stockholders.

Mr. Mitchell was awarded 1,371 restricted stock units. Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock. The restricted stock units vest in a single annual installment on the earlier of (i) June 10, 2027 or (ii) the date of the Issuer's 2027 annual meeting of stockholders. The restricted stock units may be settled only by delivering shares of the Issuer's common stock, and thus, the grant is being reported in Table 1 as allowed per SEC guidance.

The shares subject to this option shall vest in twelve (12) equal monthly installments occurring on the 10th day of each month, with the first such installment occurring on July 10, 2026 and the final such installment occurring on the earlier of (i) June 10, 2027 or (ii) the date of the Issuer's 2027 annual meeting of stockholders.

The shares subject to this option shall vest in twelve (12) equal monthly installments occurring on the 10th day of each month, with the first such installment occurring on July 10, 2026 and the final such installment occurring on the earlier of (i) June 10, 2027 or (ii) the date of the Issuer's 2027 annual meeting of stockholders.

Mr. Arbuckle was awarded 1,371 restricted stock units. Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock. The restricted stock units vest in a single annual installment on the earlier of (i) June 10, 2027 or (ii) the date of the Issuer's 2027 annual meeting of stockholders. The restricted stock units may be settled only by delivering shares of the Issuer's common stock, and thus, the grant is being reported in Table 1 as allowed per SEC guidance.

Dr. Chodakewitz was awarded 1,371 restricted stock units. Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock. The restricted stock units vest in a single annual installment on the earlier of (i) June 10, 2027 or (ii) the date of the Issuer's 2027 annual meeting of stockholders. The restricted stock units may be settled only by delivering shares of the Issuer's common stock, and thus, the grant is being reported in Table 1 as allowed per SEC guidance.

Mr. Norden was awarded 1,371 restricted stock units. Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock. The restricted stock units vest in a single annual installment on the earlier of (i) June 10, 2027 or (ii) the date of the Issuer's 2027 annual meeting of stockholders. The restricted stock units may be settled only by delivering shares of the Issuer's common stock, and thus, the grant is being reported in Table 1 as allowed per SEC guidance.

Mr. Young was awarded 1,371 restricted stock units. Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock. The restricted stock units vest in a single annual installment on the earlier of (i) June 10, 2027 or (ii) the date of the Issuer's 2027 annual meeting of stockholders. The restricted stock units may be settled only by delivering shares of the Issuer's common stock, and thus, the grant is being reported in Table 1 as allowed per SEC guidance.

The shares subject to this option shall vest in twelve (12) equal monthly installments occurring on the 10th day of each month, with the first such installment occurring on July 10, 2026 and the final such installment occurring on the earlier of (i) June 10, 2027 or (ii) the date of the Issuer's 2027 annual meeting of stockholders.

Mr. Kindler was awarded 1,371 restricted stock units. Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock. The restricted stock units vest in a single annual installment on the earlier of (i) June 10, 2027 or (ii) the date of the Issuer's 2027 annual meeting of stockholders. The restricted stock units may be settled only by delivering shares of the Issuer's common stock, and thus, the grant is being reported in Table 1 as allowed per SEC guidance.

The shares subject to this option shall vest in twelve (12) equal monthly installments occurring on the 10th day of each month, with the first such installment occurring on July 10, 2026 and the final such installment occurring on the earlier of (i) June 10, 2027 or (ii) the date of the Issuer's 2027 annual meeting of stockholders.

The shares subject to this option shall vest in twelve (12) equal monthly installments occurring on the 10th day of each month, with the first such installment occurring on July 10, 2026 and the final such installment occurring on the earlier of (i) June 10, 2027 or (ii) the date of the Issuer's 2027 annual meeting of stockholders.

These shares were acquired under the Praxis Precision Medicines, Inc. Employee Stock Purchase Plan in transactions that were exempt under both Rule 16b-3(d) and Rule 16b-3(c).

These shares were acquired under the Praxis Precision Medicines, Inc. Employee Stock Purchase Plan in transactions that were exempt under both Rule 16b-3(d) and Rule 16b-3(c).

These shares were acquired under the Praxis Precision Medicines, Inc. Employee Stock Purchase Plan in transactions that were exempt under both Rule 16b-3(d) and Rule 16b-3(c).

These shares were acquired under the Praxis Precision Medicines, Inc. Employee Stock Purchase Plan in transactions that were exempt under both Rule 16b-3(d) and Rule 16b-3(c).

These shares were acquired under the Praxis Precision Medicines, Inc. Employee Stock Purchase Plan in transactions that were exempt under both Rule 16b-3(d) and Rule 16b-3(c).

The shares subject to this option shall vest in equal monthly installments occurring on the 26th day of each month, with the first such installment occurring on February 26, 2026 and the final such installment occurring on the earlier of (i) June 26, 2026 or (ii) the date of the Issuer's 2026 annual meeting of stockholders.

The shares subject to this option shall vest in equal monthly installments occurring on the 26th day of each month, with the first such installment occurring on February 26, 2026 and the final such installment occurring on the earlier of (i) June 26, 2026 or (ii) the date of the Issuer's 2026 annual meeting of stockholders.

Mr. Arbuckle was awarded 688 restricted stock units. Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock. The restricted stock units vest in two equal annual installments occurring on the first two anniversaries of January 8, 2026. The restricted stock units may be settled only by delivering shares of the Issuer's common stock, and thus, the grant is being reported in Table 1 as allowed per SEC guidance.

Mr. Kindler was awarded 478 restricted stock units. Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock. The restricted stock units vest in a single annual installment on the earlier of (i) June 26, 2026 or (ii) the date of the Issuer's 2026 annual meeting of stockholders. The restricted stock units may be settled only by delivering shares of the Issuer's common stock, and thus, the grant is being reported in Table 1 as allowed per SEC guidance.

Mr. Kindler was awarded 688 restricted stock units. Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock. The restricted stock units vest in two equal annual installments occurring on the first two anniversaries of January 8, 2026. The restricted stock units may be settled only by delivering shares of the Issuer's common stock, and thus, the grant is being reported in Table 1 as allowed per SEC guidance.

Mr. Arbuckle was awarded 478 restricted stock units. Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock. The restricted stock units vest in a single annual installment on the earlier of (i) June 26, 2026 or (ii) the date of the Issuer's 2026 annual meeting of stockholders. The restricted stock units may be settled only by delivering shares of the Issuer's common stock, and thus, the grant is being reported in Table 1 as allowed per SEC guidance.

Shares withheld by the Issuer to satisfy the tax withholding obligations in connection with the vesting of certain previously reported restricted stock units.

Shares withheld by the Issuer to satisfy the tax withholding obligations in connection with the vesting of certain previously reported restricted stock units.

Shares withheld by the Issuer to satisfy the tax withholding obligations in connection with the vesting of certain previously reported restricted stock units.

Shares withheld by the Issuer to satisfy the tax withholding obligations in connection with the vesting of certain previously reported restricted stock units.

Shares withheld by the Issuer to satisfy the tax withholding obligations in connection with the vesting of certain previously reported restricted stock units.