Stock-Based Compensation	6 Months Ended
Jun. 30, 2018
Stock-Based Compensation [Abstract]
Stock-Based Compensation	Note 5 — Stock-Based Compensation We have a stock incentive plan for employees and others called the VirnetX Holding Corporation 2013 Equity Incentive Plan (the “Plan”), which has been approved by our stockholders. In May 2017, the Board approved an amendment and restatement of the Plan to, among other things, increase the shares reserved under the Plan by 2,500,000 shares (the “Plan Amendment”). Our stockholders approved of the Plan Amendment at the 2017 Annual Meeting of Stockholders held on June 1, 2017. The Plan provides for grants of 16,624,469 shares of our common stock, including stock options and restricted stock units (“RSUs”), and will expire in 2023. As of June 30, 2018, 1,780,315 shares remained available for grant under the Plan. During the three months ended June 30, 2018, we granted options for a total of 336,000 shares with a weighted average grant date fair value of $2.31 per options. During the three months ended June 30, 2017, we granted options totaling 331,000 shares with a weighted average grant date fair value of $2.72. During the six months ended June 30, 2018, we granted options for a total of 1,006,000 shares. The weighted average fair value at the grant dates for options issued during the six months ended June 30, 2018 was $2.52 per option. The fair values of options at the grant date were estimated utilizing the Black-Scholes valuation model with the following weighted average assumptions for the six months ended June 30, 2018 (i) dividend yield on our common stock of 0 percent (ii) expected stock price volatility of 85 percent (iii) a risk-free interest rate of 2.65 percent and (iv) and expected option term of 6 years. During the six months ended June 30, 2017, we granted options for a total of 356,000 shares with a weighted average grant date fair value of $2.65. The fair values of options at the grant date were estimated utilizing the Black-Scholes valuation model with the following weighted average assumptions for the six months ended June 30, 2017 (i) dividend yield on our common stock of 0 percent (ii) expected stock price volatility of 84 percent (iii) a risk-free interest rate average of 1.94 percent and (iv) an expected option term of 6 years. During the three months ended June 30, 2018 and 2017, we granted 223,997 and 220,664 RSUs, respectively. The weighted average fair values at the grant dates for RSUs issued during the three months ended June 30, 2018 and 2017 were $3.19 and $3.83 per RSU, respectively. RSUs, which are subject to forfeiture if service terminates prior to the shares vesting, are expensed ratably over the vesting period. During the three months ended June 30, 2018 and 2017, we paid $33 and $29 in withholding taxes on shares issued upon conversion of RSUs. The underlying shares were canceled. These amounts are reflected as financing costs in the accompanying statement of cash flows. During the six months ended June 30, 2018 and 2017, we granted 243,997 and 220,664 RSUs, respectively. The weighted average fair values at the grant dates for RSUs issued during the six months ended June 30, 2018 and 2017 were $3.28 and $3.83 per RSU, respectively. RSUs, which are subject to forfeiture if service terminates prior to the shares vesting, are expensed ratably over the vesting period. During the six months ended June 30, 2018 and 2017, we paid $33 and $29 in withholding taxes on shares issued upon conversion of RSUs. The underlying shares were canceled. These amounts are reflected as financing costs in the accompanying statement of cash flows. Stock-based compensation expense included in general and administrative expense was $467 and $855 and in research and development expense was $655 and $1,154 for the three and six months ended June 30, 2018, respectively, and $442 and $834 for general and administrative and $440 and $881 for research and development for the three and six months ended June 30, 2017, respectively. As of June 30, 2018, the unrecognized stock-based compensation expense related to non-vested stock options and RSUs was $7,160 and $2,001, respectively, which will be amortized over an estimated weighted average period of approximately 3.08 and 2.72 years, respectively. During the six-month period ended June 30, 2018 we issued 168,219 new shares of common stock as a result of vesting RSUs. No shares of common stock were issued as a result of stock options exercised during the period.

Note 5 — Stock-Based Compensation

We have a stock incentive plan for employees and others called the VirnetX Holding Corporation 2013 Equity Incentive Plan (the “Plan”), which has been approved by our stockholders. In May 2017, the Board approved an amendment and restatement of the Plan to, among other things, increase the shares reserved under the Plan by 2,500,000 shares (the “Plan Amendment”). Our stockholders approved of the Plan Amendment at the 2017 Annual Meeting of Stockholders held on June 1, 2017. The Plan provides for grants of 16,624,469 shares of our common stock, including stock options and restricted stock units (“RSUs”), and will expire in 2023. As of June 30, 2018, 1,780,315 shares remained available for grant under the Plan.

During the three months ended June 30, 2018, we granted options for a total of 336,000 shares with a weighted average grant date fair value of $2.31 per options. During the three months ended June 30, 2017, we granted options totaling 331,000 shares with a weighted average grant date fair value of $2.72.

During the six months ended June 30, 2018, we granted options for a total of 1,006,000 shares. The weighted average fair value at the grant dates for options issued during the six months ended June 30, 2018 was $2.52 per option. The fair values of options at the grant date were estimated utilizing the Black-Scholes valuation model with the following weighted average assumptions for the six months ended June 30, 2018 (i) dividend yield on our common stock of 0 percent (ii) expected stock price volatility of 85 percent (iii) a risk-free interest rate of 2.65 percent and (iv) and expected option term of 6 years.

During the six months ended June 30, 2017, we granted options for a total of 356,000 shares with a weighted average grant date fair value of $2.65. The fair values of options at the grant date were estimated utilizing the Black-Scholes valuation model with the following weighted average assumptions for the six months ended June 30, 2017 (i) dividend yield on our common stock of 0 percent (ii) expected stock price volatility of 84 percent (iii) a risk-free interest rate average of 1.94 percent and (iv) an expected option term of 6 years.

During the three months ended June 30, 2018 and 2017, we granted 223,997 and 220,664 RSUs, respectively. The weighted average fair values at the grant dates for RSUs issued during the three months ended June 30, 2018 and 2017 were $3.19 and $3.83 per RSU, respectively. RSUs, which are subject to forfeiture if service terminates prior to the shares vesting, are expensed ratably over the vesting period. During the three months ended June 30, 2018 and 2017, we paid $33 and $29 in withholding taxes on shares issued upon conversion of RSUs. The underlying shares were canceled. These amounts are reflected as financing costs in the accompanying statement of cash flows.

During the six months ended June 30, 2018 and 2017, we granted 243,997 and 220,664 RSUs, respectively. The weighted average fair values at the grant dates for RSUs issued during the six months ended June 30, 2018 and 2017 were $3.28 and $3.83 per RSU, respectively. RSUs, which are subject to forfeiture if service terminates prior to the shares vesting, are expensed ratably over the vesting period. During the six months ended June 30, 2018 and 2017, we paid $33 and $29 in withholding taxes on shares issued upon conversion of RSUs. The underlying shares were canceled. These amounts are reflected as financing costs in the accompanying statement of cash flows.

Stock-based compensation expense included in general and administrative expense was $467 and $855 and in research and development expense was $655 and $1,154 for the three and six months ended June 30, 2018, respectively, and $442 and $834 for general and administrative and $440 and $881 for research and development for the three and six months ended June 30, 2017, respectively.

As of June 30, 2018, the unrecognized stock-based compensation expense related to non-vested stock options and RSUs was $7,160 and $2,001, respectively, which will be amortized over an estimated weighted average period of approximately 3.08 and 2.72 years, respectively.

During the six-month period ended June 30, 2018 we issued 168,219 new shares of common stock as a result of vesting RSUs. No shares of common stock were issued as a result of stock options exercised during the period.