Note 10. Stockholders' Equity

Equity Issuances

December 2017 Offering

During the year ended June 30, 2018, the Company sold a total of 2,640,819 shares of its common stock at $5.50 per share in a private placement for aggregate gross proceeds of $14.5 million before deducting commissions and expenses of approximately $1.3 million. In addition to the commissions and expenses paid, the Company issued to the placement agents warrants to purchase 154,177 shares of the Company's common stock. The warrants represent a cost of the offering, have a grant date fair value of $646 thousand and are shown as an offset on the consolidated statements of changes in stockholders' equity.  

The fair values of the warrants were estimated at the dates of grant using a binomial option pricing model with the following weighted average assumptions:

Investors in the December 2017 Offering (other than directors, officers, employees, or other affiliates of the Company) were given price-protected anti-dilution rights such that if, prior to September 30, 2018, the Company issued additional shares of Common Stock or Common Stock equivalents (subject to customary exceptions, including but not limited to issuances of awards under equity compensation plans and certain other issuances of securities in connection with credit arrangements, equipment financings, lease arrangements or similar transactions) for a consideration per share less than the December 2017 Offering price per share (as adjusted for any subsequent stock dividend, stock split, distribution, recapitalization, reclassification, reorganization or similar event) (the "Lower Price"), each such investor would be entitled to receive from the Company additional shares of Common Stock in an amount such that, when added to the number of shares of Common Stock initially purchased by such investor, will equal the number of shares of Common Stock that such investor's subscription amount would have purchased at the greater of the Lower Price and $5.00 (or $4.40 in the case of one investor).  

During the year ended June 30, 2018, the Company also issued 542,450 shares of its common stock to investors in the Company's private placement offering that closed in May 2017. These issuances were made pursuant to the price-protection provisions granted to such investors in their subscription agreements.

October 2018 Offering

During the quarter ended December 31, 2018, the Company sold a total of 7,250,000 shares of its common stock at a price to the public of $4.25 per share for aggregate gross proceeds of $30.8 million before deducting the underwriting discount and offering expenses payable by the Company of approximately $2.1 million. The Company expects to use the proceeds of the offering to fund the Company's operations and growth of its business, including for capital expenditures, working capital, research and development, the commercialization of its technology and other general corporate purposes.

During the year ended June 30, 2019, the Company also issued 113,592 shares of its common stock to investors in the Company's private placement that closed in May 2017. These issuances were made pursuant to the price-protection provisions granted to such investors in their subscription agreements.  

Equity incentive plans

On May 22, 2015, the Board of Directors adopted, and on the same date the stockholders approved, the 2015 Equity Incentive Plan (the "2015 Plan"), which reserved a total of 1,200,000 shares of common stock for issuance under the 2015 Plan. The 2015 Plan authorized the grant to participants of nonqualified stock options, incentive stock options, restricted stock awards, restricted stock units, performance grants. Effective December 15, 2016, equity awards were granted under the Company's 2016 Stock Incentive Plan (the "2016 Plan"), which was approved stockholders on the same date. Effective November 1, 2018, equity awards are granted under the Company's 2018 Stock Incentive Plan (the "2018 Plan"), which was approved stockholders on the same date. No additional shares will be issued under the 2015 Plan or the 2016 Plan. The Company settles awards issued under all plans with newly issued common shares.

In addition, the number of shares of our common stock subject to the 2015 Plan, 2016 Plan and 2018 Plan, any number of shares subject to any numerical limit in the Plans, and the number of shares and terms of any incentive awards thereunder would be adjusted in the event of any change in our outstanding common stock by reason of any stock dividend, spin-off, split-up, stock split, reverse stock split, recapitalization, reclassification, merger, consolidation, liquidation, business combination or exchange of shares or similar transaction.

Options granted under the 2015 Plan, 2016 Plan and 2018 Plan vest as determined by the Company's board of directors and expire over varying terms, but not more than ten years from the date of grant. In the case of an Incentive Stock Option that is granted to a 10% shareholder on the date of grant, such Option shall not be exercisable after the expiration of five years from the date of grant.

The fair values of the Company's options were estimated at the dates of grant using a Black-Scholes option pricing model with the following weighted average assumptions:

Expected term: The Company's expected term is based on the period the options are expected to remain outstanding. The Company estimated this amount utilizing the "Simplified Method" in that the Company does not have sufficient historical experience to provide a reasonable basis to estimate an expected term.

Risk-free interest rate: The Company uses the risk-free interest rate of a U.S. Treasury Note with a similar term on the date of the grant.

Volatility: The Company calculates the expected volatility of the stock price using the historical volatilities of the Company's common stock traded on the Nasdaq Capital Market.

Dividend yield: The Company uses a 0% expected dividend yield as the Company has not paid dividends to date and does not anticipate declaring dividends in the near future.

The following is a summary of the option activity:

The total intrinsic value of options exercised during the fiscal years ended June 30, 2019 and June 30, 2018 was $20 thousand and $0, respectively.

As of June 30, 2019, the Company has $2.8 million in unrecognized stock-based compensation expense attributable to the outstanding options, which will be amortized over a period of two years.

For the years ended June 30, 2019 and 2018, the Company recorded $7.2 million and $5.5 million, respectively, in stock-based compensation which is reflected in total operating expenses in the consolidated statements of operations as follows (in thousands):

Restricted Stock Units and Restricted Stock Awards

A summary of unvested restricted stock awards ("RSAs") and restricted stock unit awards ("RSUs") outstanding as of June 30, 2019 and changes during the year ended is as follows:

The weighted average grant date fair value per share for awards granted during the fiscal years ended June 30, 2019 and June 30, 2018 was $6.21 and $6.61, respectively. The total fair value of restricted awards that vested during the fiscal years ended June 30, 2019 and June 30, 2018 was $4.9 million and $3.8 million, respectively.

During the years ended June 30, 2019 and 2018, the Company recorded stock-based compensation expense of $4.2 million and $3.8 million, respectively related to the RSAs and RSUs that have been issued to date.

As of June 30, 2019, the Company had approximately $4.2 million in unrecognized stock-based compensation expense related to the unvested shares.

Performance Awards

In September 2018 the Company granted 119,500 performance-based restricted stock units (PBRSU) to employees with a grant date fair value per share of $8.30. The PBRSU awards contain performance and service conditions which must be satisfied for an employee to earn the award. The performance condition is based primarily on the achievement of certain performance objectives. Once earned, the PBRSU awards vest 100% on the first anniversary of the grant date. The Company recognizes compensation expense for PBRSU awards using a graded vesting model, based on the probability of the performance condition being met. During the year, 119,500 of the PBRSU awards were earned.

A summary of unvested PBRSU's outstanding as of June 30, 2019 and changes during the year ended is as follows:

The weighted average grant date fair value per share for awards granted during the fiscal years ended June 30, 2019 and June 30, 2018 was $8.30 and $6.26, respectively. The total fair value of restricted awards that vested during the fiscal years ended June 30, 2019 and June 30, 2018 was $0.1 million and $0, respectively.

During the years ended June 30, 2019 and 2018, the Company recorded stock-based compensation expense of $0.63 million and $0.03 million, respectively related to the PBRSU awards that have been issued to date.

As of June 30, 2019, the Company had approximately $177 thousand in unrecognized stock-based compensation expense related to the 120 thousand unvested PBRSU awards.

Employee Stock Purchase Plan

Effective November 1, 2018, the Company adopted the Akoustis Technologies, Inc. Employee Stock Purchase Plan 2018 (the "ESPP"), which was approved by the stockholders on the same date, The ESPP is intended to qualify as an "employee stock purchase plan" under Section 423 of the Code. All regular full-time employees of the Company (including officers) and all other employees who meet the eligibility requirements of the plan may participate in the ESPP. The ESPP provides eligible employees an opportunity to acquire the Company's common stock at 85.0% of the lower of the closing price per share of the Company's common stock on the first or last day of each six-month purchase period. At June 30, 2019, 0.48 million shares were available for future issuance under this plan. The Company makes no cash contributions to the ESPP but bears the expenses of its administration. The Company issued 0.02 million, and 0.0 million shares under the ESPP in fiscal years 2019 and 2018, respectively. The Company settles awards issued under the ESPP with newly issued common shares. 

For the years ended June 30, 2019 and 2018, the Company recorded $0.04 million and $0.00 million, respectively, in stock-based compensation related to grants of ESPP shares.