In May 2011, we granted 30,000 ordinary shares to each of our four non-executive directors, of which 10,000 ordinary shares vest for each director on July 1 of each year from 2011 to 2013 so long as such director continues his service as of such date. An aggregate of 40,000 ordinary shares vested in each of July 2011, July 2012 and July 2013, respectively. The fair value of the shares granted was US$6.03 per share, being the market price on the date of the grant.
In February 2006, Red 5 adopted a Stock Incentive Plan, or Red 5 Stock Incentive Plan, under which Red 5 may grant to its employees, director and consultants stock options to purchase common stocks or restricted stocks of Red 5. Red 5 granted options to purchase an aggregate of 28,963,258 shares of common stock under the Red 5 Stock Incentive Plan from April 6, 2010 to December 31, 2013. In September 2012, Red 5 granted an aggregate of 6,122,435 restricted common stocks to two directors of Red 5 including Mr. Zhu for their services to Red 5. We measure the share-based compensation based on the fair value of the award as of the grant date. We measure the fair value of the stock options using the Black-Scholes option-pricing model with assumptions made regarding the fair value of the common stock, expected term, volatility, risk-free interest rate, and dividend yield.
In January 2018, we granted 8,250,000 options to directors, officers and consultants, of which 5,750,000 shares would vest based on their services period with our company and 2,500,000 shares granted would vest subject to their performance condition. We measured the fair value of the options using the Black-Scholes option-pricing model. In September 2018, we canceled a total of 6,200,000 shares granted in January 2018.
In September 2018 our board granted an aggregate amount of 30,000,000 restricted shares to our directors, officers and consultant. In exchange for such restricted shares grant, we forfeited and cancelled the stock options in the total amount of 6,200,000 shares previously granted to our directors in January 2018. In January 2019, our board of directors approved to forfeit and cancel 15,000,000 out of 30,000,000 restricted shares previously granted.
On June 17, 2020, our board of directors and board committees authorized and approved the issuance of an aggregate number of 29,100,000 restricted Class A ordinary shares of our company to certain directors, officers, employees and consultants of our company as share incentive awards for their services to us pursuant to our Eighth Amended and Restated 2004 Stock Option Plan. Among those restricted Class A ordinary shares grants, 15,600,000 restricted Class A ordinary shares are subject to restrictions on transferability that would be removed once certain pre-agreed performance targets are met, and 13,500,000 restricted Class A ordinary shares are subject to restrictions on transferability for a six-month period that would be removed in installments once certain service period conditions are met. All the restrictions attached to those shares have been removed upon the satisfaction of the underlying targets and conditions.
In February 2021, our board of directors and board committees authorized and approved the issuance of an aggregate number of 33,090,000 Class A ordinary shares of our company to certain directors, executive officers, employees and consultants of our company as share incentive awards for their services to us pursuant to the Option Plan. Among those Class A ordinary shares grants, 32,190,000 shares were restricted Class A ordinary shares, subject to restrictions on transferability to be removed upon the satisfaction of the conditions that half of the restricted shares should vest if our market capitalization reaches US$400 million and the other half should vest if our market capitalization reaches US$500 million. We also granted 900,000 restricted Class A ordinary share units to our directors which are immediately vested and issued the same number of shares.
In September 2021, our board of directors and board committees authorized and approved the issuance of an aggregate number of 44,290,560 Class A ordinary shares of our company to certain directors, executive officers, employees and consultants of our company as share incentive awards for their services to us pursuant to the Option Plan. Among those Class A ordinary shares grants, 44,290,560 shares were restricted Class A ordinary shares, subject to the following vesting condition: restricted shares shall vest within two years, i.e., 1/24th of all restricted share grants shall vest on the last day of each month after the date of the grant. We also granted 4,950,000 restricted Class A ordinary share units to our directors which are immediately vested and issued the same number of shares.
Share-based compensation expenses of RMB21.3 million, RMB55.1 million and RMB150.2 million (US$23.6 million) were recognized for the year ended December 31, 2019, 2020 and 2021, respectively, for options and restricted shares granted to our company’s and its subsidiaries’ employees and directors, including compensation cost due to the acceleration vesting and exercise of options in June 2017.