The fair value for options granted at the time of issuance were estimated at the date of grant using a Black-Scholes options pricing model. Significant assumptions included in the option value model include the fair value of our common stock at the grant date, weighted average volatility, risk-free interest rate, dividend yield and the forfeiture rate. There were no stock options granted in any of the periods presented.


		Weighted-Average		Contractual Terms
	Options	Exercise Price		(in Years)
Outstanding at January 1, 2020	70,628	$	30.97	1.2
Exercised	(41,370)	30.97

Outstanding at June 30, 2020	29,258	$	30.97	1.2

Options generally include a time-based vesting schedule permitting the options to vest ratably over three years. At June 30, 2020 and December 31, 2019, all options were fully vested.

There was no stock-based compensation expense on stock options for the three and six months ended June 30, 2020 and 2019, respectively.


		Weighted-Average
		Remaining
	Restricted	Contractual Terms
	Stock	(in Years)
Outstanding at January 1, 2020	318,002	1.7
Granted	158,310
Forfeited	(568)
Vested	(38,397)
Outstanding at June 30, 2020	437,347	1.6
Restricted stock exercisable at June 30, 2020	—

At June 30, 2020, there was $9,865 of unrecognized compensation expense remaining related to our service-based restricted stock awards. The unrecognized compensation cost was expected to be recognized over a weighted-average period of 1.6 years or earlier upon an elimination of the restriction period as a result of a change in control event.

Stock-based compensation expense on restricted stock amounted to $2,495 and $692 for the three months ended June 30, 2020 and 2019, respectively, and $3,453 and $1,163 for the six months ended June 30, 2020 and 2019, respectively. The increase in the stock compensation expense for the three months ended June 30, 2020 was due to a one-time stock grant to the Company's Chief Executive Officer that vested immediately resulting in an additional $1,322 of expense.


		Weighted-Average
	Warrants	Exercise Price
Outstanding at January 1, 2020	404	$	30.97

Outstanding at June 30, 2020	404	$	30.97

For all periods presented, the warrants were issued at an exercise prices of $30.97 per share. The warrants have a ten-year term. At June 30, 2020, no warrants had been exercised. At inception, no fair value was assigned to the warrants.