During the six months ended June 30, 2020, the Company granted restricted share units of 11,475 and 800,000 stock option grants at an average strike price of $15.49. During the six months ended June 20, 2019, the Company granted restricted share units of 16,365 and 553,000 stock option grants at an average strike price of $6.67. As of June 30, 2020 and December 31, 2019, there were 408,000 shares and 217,000 shares, respectively available for grants under the Plan.
Stock-based compensation expense for the three months ended June 30, 2020 and 2019 was $612,000 and $267,000, respectively, and for the six months ended June 30, 2020 and 2019 was $1.1 million and $503,000. Stock-based compensation expense is included in selling, general and administrative expenses in the Condensed Consolidated Statements of Operations.
During the three and six months ended June 30, 2020, the Company issued 176,708 and 317,774 shares, respectively, related to the vesting of restricted shares and the exercising of stock options. During the three and six months ended June 30, 2019, the Company issued 9,000 and 17,460 shares, respectively, related to the vesting of restricted shares and the exercising of stock options.
In October 2018, the Board of Directors of the Company approved the Mastech Digital, Inc. 2019 Employee Stock Purchase Plan (the “Stock Purchase Plan”). The Stock Purchase Plan is intended to meet the requirements of Section 423 of the Code and had to be approved by the Company’s shareholders to be qualified. On May 15, 2019, the Company’s shareholders approved the Stock Purchase Plan. Under the Stock Purchase Plan, 600,000 shares of Common Stock (subject to adjustment upon certain changes in the Company’s capitalization) are available for purchase by eligible employees who become participants in the Stock Purchase Plan. The purchase price per share is 85% of the lesser of (i) the fair market value per share of Common Stock on the first day of the offering period, or (ii) the fair market value per share of Common Stock on the last day of the offering period.
The Company’s eligible full-time employees are able to contribute up to 15% of their base compensation into the employee stock purchase plan, subject to an annual limit of $25,000 per person. Employees are able to purchase Company common stock at a 15% discount to the lower of the fair market value of the Company’s common stock on the initial or final trading dates of each six-month offering period. Offering periods begin on January 1 and July 1 of each year. The Company uses the Black-Scholes option pricing model to determine the fair value of employee stock purchase plan share-based payments. The fair value of the six-month “look-back” option in the Company’s employee stock purchase plans is estimated by adding the fair value of 15% of one share of stock to 85% of the fair value of an option on one share of stock. The Company utilized U.S. Treasury yields as of the grant date for its risk-free interest rate assumption, matching the Treasury yield terms to the six-month offering period. The Company utilized historical company data to develop its dividend yield and expected volatility assumptions.
During the three months and six months ended June 30, 2020 and 2019, there were 11,735 shares (the third offering period ended June 30, 2020) and 25,793 shares (the first offering period ended June 20, 2019) issued under the Stock Purchase Plan at a share price of $8.97 and $4.04, respectively. Stock-based compensation expense related to the third offering period totaled $37,000 and stock-based compensation expense related to the first offering period totaled $42,000 and is included in selling, general and administrative expenses in the Condensed Consolidated Statements of Operations for the six months ended June 30, 2020 and 2019. At June 30, 2020, there were 547,765 shares available for grants under the Plan.
On July 13, 2017, the Company entered into a Credit Agreement (as amended, the “Credit Agreement”) with PNC Bank, as administrative agent, swing loan lender and issuing lender, PNC Capital Markets LLC, as sole lead arranger and sole book-runner, and certain financial institution parties thereto as lenders (the “Lenders”). The Credit Agreement provides for a total aggregate commitment of $60 million, consisting of (i) a revolving credit facility (the “Revolver”) in an aggregate principal amount not to exceed $22.5 million (subject to increase by up to an additional $10 million upon satisfaction of certain conditions); (ii) a $30.5 million term loan facility (the “Term Loan”); and a (iii) $7.0 million delayed draw term loan facility (the “Delayed Draw Term Loan”), as more fully described in the Company’s Forms 8-K, filed with the SEC on July 19, 2017 and April 25, 2018.
The Revolver expires in July 2022 and includes swing loan and letter of credit sub-limits in the aggregate amount not to exceed $5.0 million for swing loans and $5.0 million for letters of credit. Borrowings under the Revolver may be denominated in U.S. dollars or Canadian dollars. The maximum borrowings in U.S. dollars may not exceed the sum of 85% of eligible U.S. accounts receivable and 60% of eligible U.S. unbilled receivables, less a reserve amount established by the administrative agent. The maximum borrowings in Canadian dollars may not exceed the lesser of (i) $10.0 million; and (ii) the sum of 85% of eligible Canadian receivables, plus 60% of eligible Canadian unbilled receivables, less a reserve amount established by the administrative agent.
13