(5)   Stock-Based Compensation

The Company has granted to certain of its directors, employees and employees of its subsidiaries, restricted stock, restricted stock units (“RSUs”) and options to purchase shares of the Company’s common stock (collectively, "Awards"). The Company measures the cost of employee services received in exchange for an equity classified Award (such as stock options and restricted stock) based on the grant-date fair value (“GDFV”) of the Award, and recognizes that cost over the period during which the employee is required to provide service (usually the vesting period of the Award). The Company measures the cost of employee services received in exchange for a liability classified Award based on the current fair value of the Award, and remeasures the fair value of the Award at each reporting date.

In connection with the GCI Liberty Split-Off (see note 1), the Company redeemed each outstanding share of its Series A and Series B Liberty Ventures common stock for shares of the corresponding class of GCI Liberty common stock.

Included in selling, general and administrative expenses in the accompanying condensed consolidated statements of operations are $23 million and $21 million of stock-based compensation during the three months ended June 30, 2018 and 2017, respectively, and $46 million and $37 million of stock-based compensation during the six months ended June 30, 2018 and 2017, respectively.

The following table presents the number and weighted average GDFV of options granted by the Company during the six months ended June 30, 2018:

In addition to the stock option grants to the Qurate Retail Chairman of the Board and in connection with our Chairman’s employment agreement, Qurate Retail granted performance based RSUs to him. During the six months ended June 30, 2018, Qurate Retail granted 124 thousand performance-based RSUs of Series B Qurate Retail common stock.  The RSUs had a GDFV of $27.56 per share at the time they were granted.  The performance-based RSUs cliff vest in one year, subject to the satisfaction of certain performance objectives.  Performance objectives, which are subjective, are considered in determining the timing and amount of compensation expense recognized. When the satisfaction of the performance objectives becomes probable, the Company records compensation expense. The value of the grant is remeasured at each reporting period.

The Company has calculated the GDFV for all of its equity classified Awards and any subsequent remeasurement of its liability classified Awards and certain performance-based Awards using the Black-Scholes-Merton Model. The Company estimates the expected term of the Awards based on historical exercise and forfeiture data. The volatility used in the calculation for Awards is based on the historical volatility of Qurate Retail's stock and the implied volatility of publicly traded Qurate Retail options. The Company uses a zero dividend rate and the risk-free rate for Treasury Bonds with a term similar to that of the subject options.

Qurate Retail—Outstanding Awards

The following tables present the number and weighted average exercise price ("WAEP") of the Awards to purchase Qurate Retail common stock granted to certain officers, employees and directors of the Company, as well as the weighted average remaining life and aggregate intrinsic value of the Awards.

 The grant, exercise and forfeiture/cancellation activity for Liberty Ventures Series A and B shares was immaterial during the period from January 1, 2018 through March 9, 2018, and no Awards were outstanding as of June 30, 2018. All of the outstanding Awards of Liberty Ventures Series A and B common stock were redeemed for GCI Liberty Series A and B common stock as a result of the GCI Liberty Split-Off on March 9, 2018.

As of June 30, 2018, the total unrecognized compensation cost related to unvested Awards was approximately $96 million. Such amount will be recognized in the Company's consolidated statements of operations over a weighted average period of approximately 2.3 years.

As of June 30, 2018, Qurate Retail reserved for issuance upon exercise of outstanding stock options approximately 34.2 million shares of Series A Qurate Retail common stock and 1.8 million shares of Series B Qurate Retail common stock.