STOCK BASED AWARDS

We have equity incentive plans that provide for the grant to employees and board members of stock-based awards, including stock options and restricted stock. Employee accounting applies to awards granted by the Company or subsidiary in the company or subsidiary's shares only to its own employees, respectively. No sibling or upstream awards have been granted. Stock-based compensation expense was as follows (in thousands):



	Years ended December 31,
	2019		2018		2017
Overstock restricted stock awards	$	16,160	$	9,096	$	4,056
Medici Ventures stock options	1,214		412		21
tZERO equity awards	855		4,848		—
Total stock-based compensation expense	$	18,229	$	14,356	$	4,077

Overstock restricted stock awards

The Overstock.com, Inc. Amended and Restated 2005 Equity Incentive Plan (the "Plan") provides for the grant of incentive stock options to employees and directors of the Company and non-qualified stock options to consultants, as well as restricted stock units and other types of equity awards of the Company. For the years ended December 31, 2019, 2018 and 2017, the Compensation Committee of the Board of Directors approved grants of 982,000, 387,000 and 310,000 restricted stock awards, respectively, to our officers, board members and employees. These restricted stock awards vest over three years at 33.3% at the end of the first year, 33.3% at the end of the second year and 33.3% at the end of the third year; subject to the recipient's continuing service to us. In addition to our traditional equity awards, during the quarter ended March 31, 2019, we granted 502,765 restricted stock awards with a cumulative grant date fair value of $8.6 million which vest over a one-year period, which awards are included in the 982,000 total grants above. At December 31, 2019, there were 1,051,000 unvested restricted stock awards that remained outstanding. At December 31, 2019, 1.0 million shares of stock remained available for future grants under the Plan.

The cost of restricted stock units is determined using the fair value of our common stock on the date of the grant and compensation expense is either recognized on a straight-line basis over the vesting schedule or on an accelerated schedule when vesting of restricted stock awards exceeds a straight-line basis. The cumulative amount of compensation expense recognized at any point in time is at least equal to the portion of the grant date fair value of the award that is vested at that date. The weighted average grant date fair value of restricted stock awards granted during the years ended December 31, 2019, 2018 and 2017 was $17.80, $65.42 and $17.75, respectively.

The following table summarizes restricted stock award activity (in thousands, except fair value data):



	2019				2018				2017
	Units		Weighted Average Grant Date Fair Value		Units		Weighted Average Grant Date Fair Value		Units		Weighted Average Grant Date Fair Value
Outstanding—beginning of year	559		$	44.08	540		$	17.05	560		$	17.46
Granted at fair value	982		17.80		387		65.42		310		17.75
Vested	(270	)	34.92		(234	)	17.68		(212	)	19.58
Forfeited	(220	)	23.36		(134	)	42.85		(118	)	16.21
Outstanding—end of year	1,051		$	26.22	559		$	44.08	540		$	17.05

Medici Ventures stock options

The Medici Ventures, Inc. 2017 Stock Option Plan, as amended, provides for the grant of options to employees and directors of and consultants to Medici Ventures to acquire up to 9% of the authorized shares of Medici Ventures' common stock. Medici Ventures authorized 1.5 million shares, 900,000 of which are issued and outstanding to Overstock, and 130,000 of which are subject to the 2017 Stock Option Plan. The remaining 470,000 are authorized but unissued. Options vested under this plan expire at the end of ten years. During the year ended December 31, 2019, Medici Ventures granted 27,550 stock options with a cumulative grant date fair value of $2.4 million which vest over a three-year period. During the year ended December 31, 2018, Medici Ventures granted 94,450 stock options to certain Medici Ventures and Overstock employees with a cumulative grant date fair value of $1.8 million, which will be expensed on a straight-line basis over the vesting period of three years.

tZERO equity awards

The tZERO Group, Inc. 2017 Equity Incentive Plan, as amended, provides for grant of options and restricted stock to employees and directors of and consultants to tZERO to acquire up to 5% of the authorized shares of tZERO's common stock. In January 2018, tZERO granted 2,000,000 restricted stock awards (post-stock split) with a cumulative grant date fair value of $4.0 million under the equity incentive plan, all of which vested on January 23, 2018. Accordingly, there is no expense to be recognized in future periods related to these awards. As a result of these vested awards, our indirect ownership interest in tZERO was reduced from 81% to approximately 80%. During the year ended December 31, 2019, tZERO granted options to acquire 3,477,760 shares (post-stock split) of its stock with a cumulative grant date fair value of $521,000 which will be expensed on a straight-line basis over the vesting period of three years. Options vested under this plan expire at the end of ten years. Additionally, during the year ended December 31, 2019, tZERO granted 260,500 restricted stock awards with a cumulative grant date fair value of $795,000 which will be expensed on a straight-line basis over a cliff vesting period of two years. During the year ended December 31, 2018, tZERO granted options to acquire 5,590,000 shares (post-stock split) of its stock with a cumulative grant date fair value of $4.6 million which will be expensed on a straight-line basis over the vesting period of two to three years.