10. Stockholders’ Equity

Preferred Stock – Our authorized preferred stock includes 10,000,000 shares of preferred stock with a par value of $0.001, of which no shares have been issued or are outstanding.

Common Stock – Our authorized common stock includes 200,000,000 shares of common stock with a par value of $0.001, of which 15,281,324 and 15,272,575 shares were issued and outstanding as of June 30, 2017 and December 31, 2016, respectively.

Shares Issued for Employee Stock Purchase Plan Options –

On May 23, 2017, we issued 8,749 shares to employees for $11,972 under our 2014 Employee Stock Purchase Plan (“ESPP”) for options that vested and were exercised.

Shares Issued for Consulting Services –

On September 28, 2016, we issued 418,750 fully vested restricted shares of our common stock to a third party for consulting services under a one-year contract. We recorded an expense of $837,500 for the six months ended June 30, 2017 within “Selling, general, and administrative expenses” in our condensed consolidated statement of operations. The balance recorded within “Prepaid expenses and other current assets” in our condensed consolidated balance sheet at June 30, 2017 was $209,375, which we will expense ratably through August 2017.

Warrants – During 2016, we issued warrants to purchase 521,060 shares, and no holders have exercised warrants. At June 30, 2017, we had outstanding exercisable warrants to purchase 1,733,565 shares of common stock.

The following table summarizes the warrants issued and outstanding as of June 30, 2017:

Date of

Exercise

Shares of

Description

Issuance

Expiration

Price

Common Stock

Exercisable warrants

Warrants

09/24/2014

09/24/2019

20.00

1,125,005

Warrants

10/20/2014

10/20/2019

20.00

87,500

Warrants

3/30/2016

03/30/2021

3.88

521,060

Total warrants issued and outstanding

1,733,565

Employee Stock Purchase Plan – On September 17, 2014, our stockholders approved our 2014 ESPP. We recorded expense of $7,252 and $15,466 related to the ESPP during the three months ended June 30, 2017 and 2016, respectively. We recorded expense of $8,990 and $24,672 related to the ESPP during the six months ended June 30, 2017 and 2016, respectively.

Stock Options – We recorded stock option expense of $337,230 and $1,042,170 for the six months ended June 30, 2017 and 2016, respectively. The following table summarizes the stock option activity for the six month period ended June 30, 2017:

	Stock Options
					Weighted-
				Exercise	Average
	Number			Price Per	Exercise Price
	of Shares			Share	Per Share
Outstanding at December 31, 2016		1,317,402		$2.08 — $26.00	$	9.09
Granted		79,500		$2.13 — $2.71	$	2.50
Canceled/Forfeited		(35,335	)	$6.40 — $23.20	$	12.37
Outstanding at June 30, 2017		1,361,567		$2.08 — $26.00	$	8.62