ATEC

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on November 21, 2025 to satisfy certain tax withholding obligations of the reporting person resulting from the vesting of restricted stock units.

On June 10, 2026, issuer granted to the reporting person 32,012 restricted stock units. Each restricted stock unit represents a contingent right to receive one share of issuer's common stock. The restricted stock units vest on the earlier of (a) the next annual meeting of stockholders and (b) the death or resignation of the reporting person. In the event of death or resignation of the reporting person, the grant will vest pro-rata based on the number of actual days served by the reporting person from the time of the grant to such death or resignation, divided by 365.

On June 10, 2026, issuer granted to the reporting person 32,012 restricted stock units. Each restricted stock unit represents a contingent right to receive one share of issuer's common stock. The restricted stock units vest on the earlier of (a) the next annual meeting of stockholders and (b) the death or resignation of the reporting person. In the event of death or resignation of the reporting person, the grant will vest pro-rata based on the number of actual days served by the reporting person from the time of the grant to such death or resignation, divided by 365.

On June 10, 2026, issuer granted to the reporting person 32,012 restricted stock units. Each restricted stock unit represents a contingent right to receive one share of issuer's common stock. The restricted stock units vest on the earlier of (a) the next annual meeting of stockholders and (b) the death or resignation of the reporting person. In the event of death or resignation of the reporting person, the grant will vest pro-rata based on the number of actual days served by the reporting person from the time of the grant to such death or resignation, divided by 365.

On June 10, 2026, issuer granted to the reporting person 32,012 restricted stock units. Each restricted stock unit represents a contingent right to receive one share of issuer's common stock. The restricted stock units vest on the earlier of (a) the next annual meeting of stockholders and (b) the death or resignation of the reporting person. In the event of death or resignation of the reporting person, the grant will vest pro-rata based on the number of actual days served by the reporting person from the time of the grant to such death or resignation, divided by 365.

On June 10, 2026, issuer granted to the reporting person 32,012 restricted stock units. Each restricted stock unit represents a contingent right to receive one share of issuer's common stock. The restricted stock units vest on the earlier of (a) the next annual meeting of stockholders and (b) the death or resignation of the reporting person. In the event of death or resignation of the reporting person, the grant will vest pro-rata based on the number of actual days served by the reporting person from the time of the grant to such death or resignation, divided by 365.

On June 10, 2026, issuer granted to the reporting person 32,012 restricted stock units. Each restricted stock unit represents a contingent right to receive one share of issuer's common stock. The restricted stock units vest on the earlier of (a) the next annual meeting of stockholders and (b) the death or resignation of the reporting person. In the event of death or resignation of the reporting person, the grant will vest pro-rata based on the number of actual days served by the reporting person from the time of the grant to such death or resignation, divided by 365.

The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $7.52 to $7.55, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in this footnote.

The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $7.48 to $7.50, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in this footnote.

The option vested 25% on the first anniversary of the grant date and thereafter in 36 equal monthly installments. The option expires on the tenth anniversary of the grant date.

The option vested 25% on the first anniversary of the grant date and thereafter in 36 equal monthly installments. The option expires on the tenth anniversary of the grant date.

The option vested 25% on the first anniversary of the grant date and thereafter in 36 equal monthly installments. The option expires on the tenth anniversary of the grant date.

On April 7, 2026, the reporting person exercised options to purchase 15,000 shares of the issuer's common stock for $1.98 per share, 15,000 shares of the issuer's common stock for $1.68 per share, 12,500 shares of the issuer's common stock for $3.34 per share, and 60,000 shares of the issuer's common stock for $2.69 per share. The reporting person paid the exercise price on a cashless basis, resulting in the issuer withholding 23,393 of the shares at a price of $11.03 per share to pay the applicable exercise prices for the shares and issuing to the reporting person 79,107 shares.

The option vested 25% on the first anniversary of the grant date and thereafter in 36 equal monthly installments. The option expires on the tenth anniversary of the grant date.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $12.20 to $12.42, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, 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 ranges set forth in this footnote.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 12, 2025 to satisfy certain tax withholding obligations of the reporting person resulting from the vesting of restricted stock units.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $12.21 to $12.64, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, 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 ranges set forth in this footnote.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on June 12, 2025 to satisfy certain tax withholding obligations of the reporting person resulting from the vesting of restricted stock units.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $12.13 to $12.92, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, 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 ranges set forth in this footnote.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $12.31 to $12.77, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, 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 ranges set forth in this footnote.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 5, 2025, to satisfy certain tax withholding obligations of the reporting person resulting from the vesting of restricted stock units.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $12.15 to $12.30, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, 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 ranges set forth in this footnote.

Shares withheld by the issuer to satisfy tax withholding obligations of the reporting person resulting from vesting of restricted stock units.

Shares withheld by issuer to satisfy tax withholding obligations of reporting person resulting from vesting of restricted stock units.

The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 14, 2025 to satisfy certain tax withholding obligations of the reporting person resulting from the vesting of restricted stock units.

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $12.25 to $12.86, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, 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 ranges set forth in this footnote.

Each RSU represents a contingent right to receive one share of the issuer's common stock.

On February 25, 2026, the issuer awarded 305,707 RSUs to the reporting person. The RSUs vest in three equal installments on each of March 5, 2027, March 5, 2028 and March 5, 2029.

On February 25, 2026, the issuer granted to the reporting person an award of up to 63,689 performance-based RSUs. The RSUs vest upon the issuer's (i) common stock achieving a 30-day average trading price of at least $36.00 per share at any time prior to December 31, 2030, or (ii) achievement of certain operational metrics determined by the issuer's compensation committee measured as of December 31, 2030.

Each RSU represents a contingent right to receive one share of the issuer's common stock.

Each RSU represents a contingent right to receive one share of the issuer's common stock.

On February 25, 2026, the issuer granted 20,380 RSUs to the reporting person in connection with the issuer's election to grant RSUs to the reporting person in lieu of a portion of the reporting person's 2025 cash bonus. The grant was approved and adopted by the issuer's compensation committee on February 25, 2026. The RSUs vest December 4, 2026. The grant amount was determined using the 30-day average trading price of the issuer's common stock as of close of market on February 25, 2026.

On February 25, 2026, the issuer granted to the reporting person an award of up to 63,689 performance-based RSUs. The RSUs vest upon the issuer's (i) common stock achieving a 30-day average trading price of at least $25.00 per share at any time prior to December 31, 2028, (ii) common stock achieving a 30-day average trading price of at least $36.00 per share at any time prior to December 31, 2030, (iii) achievement of certain operational metrics determined by the issuer's compensation committee measured as of December 31, 2028, or (iv) achievement of certain operational metrics determined by the issuer's compensation committee measured as of December 31, 2030.

Each RSU represents a contingent right to receive one share of the issuer's common stock.

On February 25, 2026, the issuer granted to the reporting person an award of up to 42,459 performance-based RSUs. The RSUs vest upon the issuer's (i) common stock achieving a 30-day average trading price of at least $36.00 per share at any time prior to December 31, 2030, or (ii) achievement of certain operational metrics determined by the issuer's compensation committee measured as of December 31, 2030.

Each RSU represents a contingent right to receive one share of the issuer's common stock.

On February 25, 2026, the issuer granted to the reporting person an award of up to 63,689 performance-based RSUs. The RSUs vest upon the issuer's (i) common stock achieving a 30-day average trading price of at least $25.00 per share at any time prior to December 31, 2028, (ii) common stock achieving a 30-day average trading price of at least $36.00 per share at any time prior to December 31, 2030, (iii) achievement of certain operational metrics determined by the issuer's compensation committee measured as of December 31, 2028, or (iv) achievement of certain operational metrics determined by the issuer's compensation committee measured as of December 31, 2030.

Each RSU represents a contingent right to receive one share of the issuer's common stock.

Each RSU represents a contingent right to receive one share of the issuer's common stock.

On February 25, 2026, the issuer granted 48,913 RSUs to the reporting person in connection with the issuer's election to grant RSUs to the reporting person in lieu of a portion of the reporting person's 2025 cash bonus. The grant was approved and adopted by the issuer's compensation committee on February 25, 2026. The RSUs vest December 4, 2026. The grant amount was determined using the 30-day average trading price of the issuer's common stock as of close of market on February 25, 2026.

On February 25, 2026, the issuer awarded 205,094 restricted stock units (RSUs) to the reporting person under a performance based award granted to the reporting person on January 29, 2025 upon confirmation by the issuer's compensation committee of satisfaction of certain performance criteria for the fiscal year ended December 31, 2025. The RSUs vest in three equal installments on each of March 5, 2026, March 5, 2027 and March 5, 2028.

Each RSU represents a contingent right to receive one share of the issuer's common stock.

Beneficial ownership reflects forfeiture of 32,403 previously reported RSUs for failure to satisfy applicable performance criteria.

On February 25, 2026, the issuer awarded 611,673 restricted stock units (RSUs) to the reporting person under a performance based award granted to the reporting person on January 29, 2025 upon confirmation by the issuer's compensation committee of satisfaction of certain performance criteria for the fiscal year ended December 31, 2025. The RSUs vest in three equal installments on each of March 5, 2026, March 5, 2027 and March 5, 2028.

Each RSU represents a contingent right to receive one share of the issuer's common stock.

Beneficial ownership reflects forfeiture of 103,391 previously reported RSUs for failure to satisfy applicable performance criteria.

On February 25, 2026, the issuer granted to the reporting person an award of up to 42,459 performance-based RSUs. The RSUs vest upon the issuer's (i) common stock achieving a 30-day average trading price of at least $25.00 per share at any time prior to December 31, 2028, (ii) common stock achieving a 30-day average trading price of at least $36.00 per share at any time prior to December 31, 2030, (iii) achievement of certain operational metrics determined by the issuer's compensation committee measured as of December 31, 2028, or (iv) achievement of certain operational metrics determined by the issuer's compensation committee measured as of December 31, 2030.

Each RSU represents a contingent right to receive one share of the issuer's common stock.

On February 25, 2026, the issuer awarded 311,110 restricted stock units (RSUs) to the reporting person under a performance based award granted to the reporting person on January 29, 2025 upon confirmation by the issuer's compensation committee of satisfaction of certain performance criteria for the fiscal year ended December 31, 2025. The RSUs vest in three equal installments on each of March 5, 2026, March 5, 2027 and March 5, 2028.

Each RSU represents a contingent right to receive one share of the issuer's common stock.

Each RSU represents a contingent right to receive one share of the issuer's common stock.

On February 25, 2026, the issuer awarded 127,378 RSUs to the reporting person. The RSUs vest in three equal installments on each of March 5, 2027, March 5, 2028 and March 5, 2029.

Each RSU represents a contingent right to receive one share of the issuer's common stock.

On February 25, 2026, the issuer awarded 93,410 RSUs to the reporting person. The RSUs vest in three equal installments on each of March 5, 2027, March 5, 2028 and March 5, 2029.

Each RSU represents a contingent right to receive one share of the issuer's common stock.

On February 25, 2026, the issuer awarded 127,378 RSUs to the reporting person. The RSUs vest in three equal installments on each of March 5, 2027, March 5, 2028 and March 5, 2029.

On February 25, 2026, the issuer granted to the reporting person an award of up to 152,853 performance-based RSUs. The RSUs vest upon the issuer's (i) common stock achieving a 30-day average trading price of at least $36.00 per share at any time prior to December 31, 2030, or (ii) achievement of certain operational metrics determined by the issuer's compensation committee measured as of December 31, 2030.

Each RSU represents a contingent right to receive one share of the issuer's common stock.

Each RSU represents a contingent right to receive one share of the issuer's common stock.

On February 25, 2026, the issuer granted 20,992 RSUs to the reporting person in connection with the issuer's election to grant RSUs to the reporting person in lieu of a portion of the reporting person's 2025 cash bonus. The grant was approved and adopted by the issuer's compensation committee on February 25, 2026. The RSUs vest December 4, 2026. The grant amount was determined using the 30-day average trading price of the issuer's common stock as of close of market on February 25, 2026.

Each RSU represents a contingent right to receive one share of the issuer's common stock.

On February 25, 2026, the issuer awarded 110,394 RSUs to the reporting person. The RSUs vest in three equal installments on each of March 5, 2027, March 5, 2028 and March 5, 2029.

Each RSU represents a contingent right to receive one share of the issuer's common stock.

On February 25, 2026, the issuer granted 20,380 RSUs to the reporting person in connection with the issuer's election to grant RSUs to the reporting person in lieu of a portion of the reporting person's 2025 cash bonus. The grant was approved and adopted by the issuer's compensation committee on February 25, 2026. The RSUs vest December 4, 2026. The grant amount was determined using the 30-day average trading price of the issuer's common stock as of close of market on February 25, 2026.

On February 25, 2026, the issuer granted to the reporting person an award of up to 46,705 performance-based RSUs. The RSUs vest upon the issuer's (i) common stock achieving a 30-day average trading price of at least $25.00 per share at any time prior to December 31, 2028, (ii) common stock achieving a 30-day average trading price of at least $36.00 per share at any time prior to December 31, 2030, (iii) achievement of certain operational metrics determined by the issuer's compensation committee measured as of December 31, 2028, or (iv) achievement of certain operational metrics determined by the issuer's compensation committee measured as of December 31, 2030.

Each RSU represents a contingent right to receive one share of the issuer's common stock.

On February 25, 2026, the issuer awarded 311,110 restricted stock units (RSUs) to the reporting person under a performance based award granted to the reporting person on January 29, 2025 upon confirmation by the issuer's compensation committee of satisfaction of certain performance criteria for the fiscal year ended December 31, 2025. The RSUs vest in three equal installments on each of March 5, 2026, March 5, 2027 and March 5, 2028.

Each RSU represents a contingent right to receive one share of the issuer's common stock.

Includes 368 shares acquired under issuer's employee stock purchase plan on November 14, 2025 and also reflects the forfeiture of 25,041 previously reported RSUs for failure to satisfy applicable performance criteria.

Each RSU represents a contingent right to receive one share of the issuer's common stock.

On February 25, 2026, the issuer awarded 84,918 RSUs to the reporting person. The RSUs vest in three equal installments on each of March 5, 2027, March 5, 2028 and March 5, 2029.

Each RSU represents a contingent right to receive one share of the issuer's common stock.

On February 25, 2026, the issuer granted 20,992 RSUs to the reporting person in connection with the issuer's election to grant RSUs to the reporting person in lieu of a portion of the reporting person's 2025 cash bonus. The grant was approved and adopted by the issuer's compensation committee on February 25, 2026. The RSUs vest December 4, 2026. The grant amount was determined using the 30-day average trading price of the issuer's common stock as of close of market on February 25, 2026.