Note 7 - Stockholders' Equity

3 Months Ended

Mar. 31, 2018

Notes to Financial Statements

Disclosure of Compensation Related Costs, Share-based Payments [Text Block]

7

.     

Stockholders

’

Equity

Common Stock

On

March 28, 2018,

the Company sold

609,636

shares of common stock at a price of

$2.27

per share.  The net proceeds to the Company from the sale and issuance of the shares, after deducting the offering expenses borne by the Company of approximately

$171,000,

were

$1,213,000.

  Additionally, the investors received unregistered warrants in a simultaneous private placement to purchase up to

304,818

shares of common stock.  The warrants have an exercise price of

$2.68

per share and shall be exercisable commencing

six

months following the issuance date and have a term of

5.5

years.

Stock Based Compensation

The Company recorded stock-based compensation of

$137,000

and

$247,000

for the

three

months ended

March 31, 2018

and

2017,

respectively.

The following is a summary of option activity for the Company’s stock option plans:

	Number of Shares			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Life		Aggregate Intrinsic Value
Outstanding at December 31, 2017		1,156,027		$	3.92
Granted		80,000		$	3.00
Forfeited		(2,435	)	$	3.53
Expired		(27,182	)	$	4.67
Outstanding at March 31, 2018		1,206,410		$	3.84		8.5		--
Vested and expected to vest at March 31, 2018		943,103		$	4.07		8.3		--
Exercisable at March 31, 2018		306,582		$	6.22		5.7		--

The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying awards and the quoted price of the Company’s common stock. There were

no

options exercised during the

three

months ended

March 31, 2018.

The fair value of the Company’s stock options granted for the

three

months ended

March 31, 2018

was estimated using the following weighted-average assumptions:

Expected life (years)	5.6
Risk-free interest rate	2.7	%
Expected volatility	98	%
Dividend yield	0	%

Common Stock Restricted

Units

The following is a summary of restricted stock activity during the

three

months ended

March 31, 2018:

			Weighted Average
	Number of Shares		Grant Date Fair Value
Balance at December 31, 2017		416	$	17.60
Granted		--
Vested		--
Forfeited		--
Outstanding at March 31, 2018		416	$	17.60

Warrants

A summary of warrant activity for the

three

months ended

March 31, 2018

follows:

	Number of Shares		Weighted-Average Exercise Price Per Share
Balance at December 31, 2017		4,828,723	$	9.37
Warrants granted		304,818		2.68
Warrants canceled		--		--
Warrants exercised		--		--
Outstanding at March 31, 2018		5,133,541	$	8.97
Exercisable at March 31, 2018		4,130,194	$	9.60

At

March 31, 2018,

the total intrinsic value of warrants outstanding and exercisable was

$0

.