6.	Convertible Preferred Stock

Convertible preferred stock has a par value $0.001 and was issued beginning in 2000. Each issuance is briefly described as follows:

Series A Convertible Preferred Stock (“Series A Preferred”)

In 2000, the Company issued 31,407 shares of Series A Preferred at $7.96 per share to its initial employees and consultants.

Series B Convertible Preferred Stock (“Series B Preferred”)

In 2000, the Company issued 600,999 shares of Series B Preferred at $9.01 per share in exchange for $2,200 in equipment, intellectual property, and conversion of existing debt, and $3,215 in cash, and incurred issuance costs of $43. Subsequently in 2000, the Company issued an additional 110,988 shares of Series B Preferred at $9.01 per share for cash. As part of the issuance of the Series C convertible preferred stock in June 2002, the holders of Series B Preferred agreed to modify the redemption feature of the Series B Preferred to eliminate this feature. As described below, 244,173 shares of Series B Preferred were mandatorily converted into common stock during 2012.

Series C Convertible Preferred Stock (“Series C Preferred”) and Warrants

The Company issued warrants to purchase 100,524 shares of Series C Preferred in conjunction with certain bridge loan financings during 2001 and the subsequent 2002 Series C Preferred financing. The warrants were issued with an exercise price of $0.01 per share. Two of the investors exercised such warrants during 2003.

In 2002, the Company issued 2,867,154 shares of Series C Preferred for $24,000 in cash and the conversion of approximately $4,513 of 4.5% convertible notes and accrued interest, less issuance costs of approximately $86. As described below, 197,045 shares of Series C Preferred were mandatorily converted into common stock during 2012. In January 2005, the remaining warrants to purchase 23,911 shares of Series C Preferred shares were exercised.

Series C-1 Convertible Preferred Stock (“Series C-1 Preferred”) and Warrants

In August 2004, the Company received cash of $3,200 for the issuance of 984,615 shares of Series C-1 Preferred. As described below, these Series C-1 Preferred shares were mandatorily converted into common stock during 2012.

In July 2006, the Company issued warrants to purchase 196,923 shares of Series C-1 Preferred in conjunction with a loan financing agreement. The warrants were issued with an exercise price of $3.25 per share and will expire on July 14, 2016. The fair value at the date of grant for these instruments was $459, which was recorded as a debt discount. The debt discount related to these warrants was fully amortized as of December 31, 2010. The Company determined that the warrants should be recorded as a derivative liability and stated at fair value at each reporting period. The Company recorded other income of $37 and $0 for the three months ended March 31, 2014 and 2013, respectively, related to the fair value adjustment for these warrants.

Series C-2 Convertible Preferred Stock (“Series C-2 Preferred”)

In March 2008, the Company received cash of $13,500 for the issuance of 2,347,826 shares of Series C-2 Preferred.

Series D-1 Convertible Preferred Stock (“Series D-1 Preferred) and Series D-2 Convertible Preferred Stock (“Series D-2 Preferred”)

On December 11, 2013, the Company entered into an agreement to sell 1,785,712 shares of Series D-2 Preferred at $1.40 per share for an aggregate price of $2,500 (the “Series D-2 Purchase Agreement”), less issuance costs of $95. With the sale of the Series D-2 Preferred on December 11, 2013 at a price of $1.40 per share, the antidilution provisions associated with the Series B Preferred, the Series C Preferred, the Series C-1 Preferred, and the Series C-2 Preferred were triggered. As of December 11, 2013, the conversion price of the Series B Preferred, the Series C Preferred, the Series C-1 Preferred, and the Series C-2 Preferred were reduced from $45.95, $51.77, $66.30, and $117.30, respectively, to $32.2912, $36.2386, $46.1101, and $78.9623, respectively.

The Series D-2 Purchase Agreement also included warrants to purchase 87,532 shares of the Company’s common stock at $0.20 per share. The fair value of the warrants on the date of issuance was $4,214, which was recorded as a discount to the Series D-2 Preferred. The fair value of the warrants was $1,714 above the face amount of the Series D-2 Preferred and this excess was expensed to derivative fair value adjustment at issuance. The Company calculated the fair value of the warrants as the difference between the estimated fair value of the common stock on December 11, 2013 of $48.35 per share and the exercise price per share of $0.20 multiplied by the number of shares of common stock issuable upon exercise of the warrants of 87,532. The Company determined that the warrants should be classified as a derivative liability and stated at fair value at each reporting period.

The Series D-2 Preferred was convertible into shares of common stock at a conversion price of $28.56 per share. Since the fair value of the common stock on December 11, 2013 was $48.35, the Company determined that the sale of the Series D-2 Preferred resulted in a beneficial conversion feature. The Company calculated the intrinsic value of the beneficial conversion feature as the difference between the estimated fair value of the common stock on December 11, 2013 of $48.35 per share and the effective conversion price per share of $0 multiplied by the number of shares of common stock issuable upon exercise of the warrants of 87,352. The intrinsic value was calculated at $4,232, which the Company recorded as a reduction to additional paid-in capital.

Concurrent with the sale of the Series D-2 Preferred, the Company modified the terms of the 2011-2012 Notes and the related warrants and the June 2013 Notes and related warrants (Note 4). Under the amendments, the outstanding principal and accrued interest balance was converted into Series D-1 Preferred and Series D-2 Preferred at a conversion price of $1.40 per share. As a result of the conversions, the Company issued 6,054,255 shares of Series D-1 Preferred and 3,956,985 shares of Series D-2 Preferred.

On January 31, 2014, the Company sold to related parties 388,641 shares of Series D-2 Preferred under the Series D-2 Purchase Agreement at $1.40 per share, for an aggregate price of $544. The sale also included warrants to purchase 19,048 shares of the Company’s common stock at $0.20 per share. The fair value of the warrants on the date of issuance was $906. The fair value of the warrants was $362 above the face amount of the Series D-2 Preferred and this excess was expensed to derivative fair value adjustment at issuance. The Company calculated the fair value of the warrants as the difference between the estimated fair value of the common stock on January 31, 2014 of $47.74 per share and the exercise price per share of $0.20 per share multiplied by the number of shares of common stock issuable upon exercise of the warrants of 19,048. The warrants are classified as a derivative liability and stated at fair value at each reporting period. With the sale of the Series D-2 Preferred on January 31, 2014 at a price of $1.40 per share, the antidilution provisions associated with the Series B Preferred, the Series C Preferred, the Series C-1 Preferred, and the Series C-2 Preferred were triggered. As of January 31, 2014, the conversion price of the Series B Preferred, the Series C Preferred, the Series C-1 Preferred, and the Series C-2 Preferred were reduced from $32.2912, $36.2386, $46.1101, and $78.9623, respectively, to $32.0076, $35.8917, $45.6062, and $77.9382, respectively.

Authorized, Issued, and Outstanding Preferred Shares

The following table summarizes authorized, issued, and outstanding preferred shares as of March 31, 2014:


	Authorized		Outstanding		Issue Price		Liquidation Preference
Series A Preferred		31,410		31,407	$	7.96	$	250
Series B Preferred		711,987		467,814		9.01		4,215
Series C Preferred		2,967,678		2,770,633		10.15		28,121
Series C-1 Preferred		3,076,923		—		3.25		—
Series C-2 Preferred		2,347,826		2,347,826		5.75		13,500
Series D-1 Preferred		10,000,000		6,054,255		1.40		16,952
Series D-2 Preferred		10,000,000		6,131,338		1.40		25,752

Total		29,135,824		17,803,273			$	88,790

At March 31, 2014, the convertible preferred stock has been adjusted to reflect the liquidation values shown in the table above.

Preferred Stock Activity

The following table summarizes preferred stock activity for the three months ended March 31, 2014:


	Shares of
	Series A Convertible Preferred Stock		Series B Convertible Preferred Stock		Series C Convertible Preferred Stock		Series C-1 Convertible Preferred Stock		Series C-2 Convertible Preferred Stock		Series D-1 Convertible Preferred Stock		Series D-2 Convertible Preferred Stock
Balance, December 31, 2013		31,407		467,814		2,770,633		—		2,347,826		6,054,255		5,742,697
Issuance of Series D-2 Preferred		—		—		—		—		—		—		388,641

Balance, March 31, 2014		31,407		467,814		2,770,633		—		2,347,826		6,054,255		6,131,338

Automatic Conversion of Preferred Stock

On March 13, 2014, the Company amended and restated its certificate of incorporation to require the automatic conversion of the convertible preferred stock into common stock upon the completion of a public offering of common stock with gross proceeds of at least $20,000.