Common Stock options

Prior to the Business Combination, the Company maintained its 2009 Omnibus Equity Compensation Plan (the “2009 Plan”). Upon Closing of the Business Combination, awards under the 2009 Plan were converted at the exchange ratio calculated in accordance with the Business Combination Agreement and the 2021 Stock Incentive Plan (the “2021 Plan” and together with the 2009 Plan, “the Plans”) was adopted and approved. As of September 30, 2021, there were 11,781,146 shares of Common Stock reserved under the Plans.

The following table sets forth the activity for all Common Stock options:

Restricted Stock Awards

The following table sets forth the activity for all restricted stock awards:

Restricted Stock Units

As part of the consideration in the Business Combination, RSUs with respect to 1,750,000 shares of Common Stock were granted to the participants in Legacy Airspan’s MIP. For the RSUs granted to MIP Participants, the weighted average grant date fair value was $9.75. The RSUs granted in connection with the MIP vest one year after the date of the grant.

Because the Company maintained a full valuation allowance on its U.S. deferred tax assets, it did not recognize any tax benefit related to share-based compensation expense for the three and nine months ended September 30, 2021 and 2020. As of September 30, 2021, there was $4.2 million of unrecognized compensation expense related to stock options to be recognized over a weighted average period of 2.25 years and $1.0 million of unrecognized compensation expense related to restricted stock awards to be recognized over a weighted average period of 8.37 years.

The following table summarizes the number of authorized, unissued shares of Common Stock, under all employee stock plans, to be issued upon exercise as of September 30, 2021:

The following table summarizes share-based compensation expense for the three and nine months ended September 30, 2021 and 2020 (in thousands):