(6) Stock-Based Compensation

Liberty Broadband grants, to certain of its directors, employees and employees of its subsidiaries, restricted stock and stock options to purchase shares of its 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. 

Included in the accompanying condensed consolidated statements of operations are the following amounts of stock-based compensation for the three months ended March 31, 2019 and 2018 (amounts in thousands):

Liberty Broadband – Grants of Stock Options

During the three months ended March 31, 2019, Liberty Broadband granted 41 thousand options to purchase shares of Series C Liberty Broadband common stock and 25 thousand performance-based restricted stock units (“RSUs”) of Series C Liberty Broadband common stock to our CEO. Such options had a GDFV of $25.46 per share. The RSUs had a GDFV of $88.99 per share at the time they were granted. The options vest on December 31, 2019, and the RSUs cliff vest in one year, subject to satisfaction of certain performance objectives. Performance objectives, which are subjective, are considered in determining the timing and amount of the compensation expense recognized. When the satisfaction of the performance objectives becomes probable, the Company records compensation expense. The probability of satisfying the performance objectives is assessed at the end of each reporting period.

There were no options to purchase shares of Series A or Series B common stock granted during the three months ended March 31, 2019.  

The Company calculates the GDFV for all of its equity classified awards and any subsequent remeasurement of its liability classified awards using the Black-Scholes 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 Liberty Broadband common stock and the implied volatility of publicly traded Liberty Broadband 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.

Liberty Broadband – Outstanding Awards

The following tables present the number and weighted average exercise price (“WAEP”) of Awards to purchase Liberty Broadband 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.

As of March 31, 2019, the total unrecognized compensation cost related to unvested Awards was approximately $4.4 million. Such amount will be recognized in the Company's condensed consolidated statements of operations over a weighted average period of approximately 1.0 year. 

As of March 31, 2019, Liberty Broadband reserved 2.7 million shares of Series A and Series C common stock for issuance under exercise privileges of outstanding stock Awards.

Skyhook Equity Incentive Plans

Long-Term Incentive Plans

Skyhook has a long-term incentive plan which provides for the granting of phantom stock appreciation rights (“PARs”) and phantom stock units (“PSUs”) to employees, directors, and consultants of Skyhook that is not significant to Liberty Broadband. As of March 31, 2019 and December 31, 2018, $1.2 million and $1.1 million, respectively, are included in other liabilities for the fair value (Level 2) of the Company’s long-term incentive plan obligations.