Note 7 - Equity Award Plans

3 Months Ended

Mar. 31, 2019

Notes to Financial Statements

Shareholders' Equity and Share-based Payments [Text Block]

7.

Equity Award Plans

In

April 2006,

the Company’s Board of Directors (the “Board”) adopted and the stockholders approved the

2006

Stock Option Plan (

“2006

Plan”), which provided for the grant of incentive and non-statutory stock options. In

February 2013

the Board adopted and the stockholders approved the

2013

Equity Incentive Plan (

“2013

Plan”), which became effective on

March 21, 2013.

At that time, the Company ceased to grant equity awards under the

2006

Plan. Under the

2013

Plan,

643

shares of common stock were originally reserved for issuance. Additionally, all reserved and unissued shares under the

2006

Plan are eligible for issuance under the

2013

Plan. The

2013

Plan authorizes the award of incentive and non-statutory stock options, restricted stock awards, stock appreciation rights, restricted stock units ("RSUs"), performance awards and stock bonuses to the Company’s employees, directors, consultants, independent contractors and advisors. On

January 1

of each calendar year through

2023,

the number of shares of common stock reserved under the

2013

Plan will automatically increase by an amount equal to

5%

of the total outstanding shares as of the immediately preceding

December 

31,

or such lesser number of shares as determined by the Board. Pursuant to terms of the

2013

Plan, the shares available for issuance increased by

297

shares of common stock on

January 

1,

2019.

As of

March 31, 2019,

1,162

shares of common stock were reserved for issuance under the

2013

Plan.

Stock Options

A summary of stock option activity under the

2006

Plan and

2013

Plan is as follows:

	Options Outstanding
	Number of Shares			Weighted Average Exercise Price Per Share		Weighted Average Remaining Contractual Term (in Years)		Aggregate Intrinsic Value
Balances at December 31, 2018		436		$	29.01		6.79	$	—
Options forfeited and cancelled		(6	)		63.58		—		—
Balances at March 31, 2019		430			28.49		6.60		—
Options exercisable		310			35.71		5.83		—
Options vested		310			35.70		5.83		—
Options vested and expected to vest		419			28.93		6.55		—

RSUs

A summary of RSUs granted and unvested under the

2013

Plan is as follows:

	RSUs Outstanding
	Number of Shares			Weighted Average Grant Date Fair Value Per Unit
Granted and unvested at December 31, 2018		834		$	7.99
RSUs granted		116			4.34
RSUs vested		(16	)		20.22
RSUs cancelled and withheld to cover taxes		(80	)		10.53
Granted and unvested at March 31, 2019		854		$	7.03

Employee Stock Purchase Plan

In

February 2013,

the Board and stockholders approved the

2013

Employee Stock Purchase Plan (

“2013

ESPP”), under which

143

shares of common stock were originally reserved for issuance. The

2013

ESPP became effective on

March 

22,

2013.

The

2013

ESPP generally provides for purchase periods each

six

months with the purchase price for shares of common stock purchased under the

2013

ESPP is

85%

of the lesser of the fair market value of the common stock on (

1

) the

first

trading day of the applicable offering period and (

2

) the last trading day of each purchase period in the applicable offering period. On

January 

1

of each calendar year following the

first

offering date, the number of shares reserved under the

2013

ESPP automatically increases by an amount equal to

1%

of the total outstanding shares as of immediately preceding

December 

31,

but

not

to exceed

100

shares. Pursuant to terms of the

2013

ESPP, the shares available for issuance increased by

59

shares on

January 

1,

2019.

As of

March 31, 2019,

213

shares were reserved for issuance under the

2013

ESPP. During the

three

months ended

March 31, 2019,

no

shares were issued under the

2013

ESPP.