Stock Based Compensation	9 Months Ended
Sep. 29, 2018
Stock Based Compensation
Stock Based Compensation	Note 8—Stock‑Based Compensation We have an incentive plan, the 2012 Plan, which provides for up to 8.8 million shares of authorized stock to be awarded as stock options, in the form of incentive stock options or nonqualified stock options, or restricted stock units (“RSUs”). The exercise price of options granted under the 2012 Plan is equal to the estimated fair market value of our common stock at the date of grant. The fair value of RSUs granted under the plan is equal to the estimated fair market value of our common stock on the date of grant. Forfeitures are recorded as they occur, and compensation expense previously recognized for an award that was forfeited is reversed in the period of the forfeiture. We estimate the fair value of stock options on the date of grant using a Black‑Scholes option‑pricing valuation model, which uses the expected option term, stock price volatility, and the risk‑free interest rate. At the time that the outstanding awards were granted, there was no active market for our common shares, and as such, volatility was estimated in accordance with Accounting Standards Codification 718 Compensation—Stock Compensation (“ASC 718”), using the historical closing values of comparable publicly held entities. The expected option term assumption reflects the period for which we believe the option will remain outstanding. This assumption is based upon the historical and expected behavior of our employees and may vary based upon the behavior of different groups of employees. The risk‑free interest rate reflects the U.S. Treasury yield curve for a similar instrument with the same expected term in effect at the time of the grant. On June 20 and 29, 2018, our Board of Directors approved the grant of an aggregate of 1,407,583 RSUs to various employees and directors, which approvals became effective on June 23 and July 2, 2018, respectively. Of the aggregate RSUs approved on June 20 and 29, 2018, 9,160 RSUs were cancelled prior to issuance. On August 22, 2018 our Board of Directors approved the grant of 27,480 RSUs to one employee, which approval became effective on August 25, 2018. As of September 29, 2018, 1,425,903 RSUs had been granted, 1,410,718 RSUs were outstanding, and 15,185 had been forfeited under the 2012 Plan. The RSUs vest upon the occurrence of a change of control and the achievement of certain EBITDA targets for calendar years 2018 and 2019, provided that if a change of control occurs prior to the date on which our Board of Directors certifies that the applicable EBITDA target has been achieved, all RSUs that have not already been forfeited will become nonforfeitable and shares of our common stock will be delivered to the applicable grantee within 30 days of the RSUs becoming nonforfeitable. 385,241 of those RSUs were granted as replacement awards in exchange for 104,411 out‑of‑the‑money stock options which were cancelled. The concurrent cancellation and replacement was a modification for accounting purposes, which GAAP requires continued recognition of the cancelled awards’ fair value plus the recognition of the new awards’ fair value for any awards likely to vest. Any incremental compensation cost resulting from the modification will not be recognized prior to the consummation of a change in control as GAAP deems satisfaction of a change in control contingency to be unlikely. We recognized $2.9 million and $2.7 million for the three months ended September 29, 2018 and September 30, 2017, respectively, of compensation expense in the accompanying consolidated statements of operations. For the nine months ended September 29, 2018 and September 30, 2017 we recognized $10.0 million and $9.2 million, respectively, of compensation expense in the accompanying consolidated statements of operations. As of September 29, 2018, total unrecognized compensation expense for unvested options totaled $9.8 million, and will be recognized over the next three years. As of September 29, 2018, total unrecognized compensation expense for unvested RSUs totaled $44.8 million, and will be recognized upon consummation of a change in control.

Note 8—Stock‑Based Compensation

We have an incentive plan, the 2012 Plan, which provides for up to 8.8 million shares of authorized stock to be awarded as stock options, in the form of incentive stock options or nonqualified stock options, or restricted stock units (“RSUs”). The exercise price of options granted under the 2012 Plan is equal to the estimated fair market value of our common stock at the date of grant. The fair value of RSUs granted under the plan is equal to the estimated fair market value of our common stock on the date of grant. Forfeitures are recorded as they occur, and compensation expense previously recognized for an award that was forfeited is reversed in the period of the forfeiture.

We estimate the fair value of stock options on the date of grant using a Black‑Scholes option‑pricing valuation model, which uses the expected option term, stock price volatility, and the risk‑free interest rate. At the time that the outstanding awards were granted, there was no active market for our common shares, and as such, volatility was estimated in accordance with Accounting Standards Codification 718 Compensation—Stock Compensation (“ASC 718”), using the historical closing values of comparable publicly held entities. The expected option term assumption reflects the period for which we believe the option will remain outstanding. This assumption is based upon the historical and expected behavior of our employees and may vary based upon the behavior of different groups of employees. The risk‑free interest rate reflects the U.S. Treasury yield curve for a similar instrument with the same expected term in effect at the time of the grant.

On June 20 and 29, 2018, our Board of Directors approved the grant of an aggregate of 1,407,583 RSUs to various employees and directors, which approvals became effective on June 23 and July 2, 2018, respectively. Of the aggregate RSUs approved on June 20 and 29, 2018, 9,160 RSUs were cancelled prior to issuance. On August 22, 2018 our Board of Directors approved the grant of 27,480 RSUs to one employee, which approval became effective on August 25, 2018. As of September 29, 2018, 1,425,903 RSUs had been granted, 1,410,718 RSUs were outstanding, and 15,185 had been forfeited under the 2012 Plan. The RSUs vest upon the occurrence of a change of control and the achievement of certain EBITDA targets for calendar years 2018 and 2019, provided that if a change of control occurs prior to the date on which our Board of Directors certifies that the applicable EBITDA target has been achieved, all RSUs that have not already been forfeited will become nonforfeitable and shares of our common stock will be delivered to the applicable grantee within 30 days of the RSUs becoming nonforfeitable. 385,241 of those RSUs were granted as replacement awards in exchange for 104,411 out‑of‑the‑money stock options which were cancelled. The concurrent cancellation and replacement was a modification for accounting purposes, which GAAP requires continued recognition of the cancelled awards’ fair value plus the recognition of the new awards’ fair value for any awards likely to vest. Any incremental compensation cost resulting from the modification will not be recognized prior to the consummation of a change in control as GAAP deems satisfaction of a change in control contingency to be unlikely.

We recognized $2.9 million and $2.7 million for the three months ended September 29, 2018 and September 30, 2017, respectively, of compensation expense in the accompanying consolidated statements of operations. For the nine months ended September 29, 2018 and September 30, 2017 we recognized $10.0 million and $9.2 million, respectively, of compensation expense in the accompanying consolidated statements of operations. As of September 29, 2018, total unrecognized compensation expense for unvested options totaled $9.8 million, and will be recognized over the next three years. As of September 29, 2018, total unrecognized compensation expense for unvested RSUs totaled $44.8 million, and will be recognized upon consummation of a change in control.