10. SHARE-BASED COMPENSATION

During 2019, the Company’s Board of Directors adopted the 2019 Stock and Incentive Plan (the “Plan”), which was amended in April 2020, March 2021 and June 2023. The Plan permits the issuance of stock options, stock appreciation rights, stock awards, share units, performance shares, performance units and other stock-based awards, and, as of March 31, 2024, 2.3 million shares have been authorized to be issued under the Plan and 0.7 million are available for future grant. The Plan provides for the grant of options as either non-statutory stock options or incentive stock options and restricted stock units to employees, officers, directors, and consultants of the Company to attract and retain persons of ability to perform services for the Company and to reward such individuals who contribute to the achievement by the Company of its economic objectives. The awards granted generally vest in 25% increments over a four-year period and option awards expire 6 years from grant date. 

The Plan is administered by the Board or a committee appointed by the Board, which determines the persons to whom the awards will be granted, the type of awards to be granted, the number of awards to be granted, and the specific terms of each grant, including the vesting thereof, subject to the provisions of the Plan.

During the three months ended March 31, 2024 and 2023, the Company granted shares to certain employees as compensation for services. These shares were accounted for in accordance with ASC 718 - Compensation - Stock Compensation. The Company amortizes awards over the service period and until awards are fully vested.

For the three months ended March 31, 2024 and 2023, share-based compensation expense was as follows:

The following table summarizes the status of stock option grants and unvested awards at and for the three months ended March 31, 2024:

The weighted-average fair value of options granted during the three months ended March 31, 2024, estimated as of the grant date were $0.16. As of March 31, 2024, there was $128 of total unrecognized compensation cost related to non-vested options, which is expected to be recognized over a remaining weighted-average vesting period of 0.9 years.

For the three months ended March 31, 2024 and 2023, the fair value of the stock options granted were determined using the Black-Scholes option-pricing model with the following weighted average assumptions at the time of grant..