The following table summarizes the outstanding stock option activity during the periods indicated:

				Weighted average
	Number of shares			Exercise price		Remaining contractual term (years)
Balance at December 31, 2018		1,407,049		$	8.73
Granted		395,485			11.39
Exercised		(128,461	)		4.58
Expired/Forfeited		(120,904	)		10.89
Balance at June 30, 2019		1,553,169		$	9.58		8.1

Vested and exercisable at June 30, 2019		701,862		$	8.19		7.1
Vested and expected to vest at June 30, 2019		1,553,169		$	9.58		8.1

The weighted average grant date fair value of options granted during the six months ended June 30, 2019 and for the year ended December 31, 2018 was $4.00 and $3.97, respectively. For fully vested stock options, the aggregate intrinsic value as of June 30, 2019 and December 31, 2018 was $4,293,000 and $2,485,000, respectively. For stock options expected to vest, the aggregate intrinsic value as of June 30, 2019 and December 31, 2018 was $2,994,000 and $993,000, respectively.

At June 30, 2019 and December 31, 2018, there was $3,255,000 and $2,781,000, respectively, of total unrecognized compensation cost related to unvested stock options granted under the Company’s equity plans. That cost is expected to be recognized over the next three years and is based on the date the options were granted.

During the six months ended June 30, 2019, the Company granted 95,478 Restricted Stock Units (RSUs) at a weighted average grant date fair value of $11.35 per share. No RSUs vested during the three and six months ended June 30, 2019. As of June 30, 2019, the Company has 96,605 RSUs outstanding at a weighted average grant date fair value of $11.42 per share and a weighted average remaining contractual term of 2.1 years. As of June 30, 2019, there was $986,000 of total unrecognized compensation cost related to unvested RSUs.

The Company currently uses authorized and unissued shares to satisfy share award exercises.