Net Loss per Share

3 Months Ended

Mar. 31, 2016

Net Loss per Share

Net Loss per Share

3.  Net Loss per Share

Basic and diluted net loss per common share is calculated by dividing net loss applicable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration of common stock equivalents.  The Company’s potentially dilutive shares, which include outstanding stock options, unvested restricted stock units, and shares issuable upon conversion of the Convertible Notes, are considered to be common stock equivalents and are only included in the calculation of diluted net loss per share when their effect is dilutive.

The following table presents amounts that were excluded from the calculation of diluted net loss per share, due to their anti-dilutive effect (in thousands):

	Three Months Ended March 31,
	2015	2016
Outstanding stock options	4,791	7,068
Unvested restricted stock units	16	537
Shares issuable upon conversion of Convertible Notes	—	20
	4,807	7,625

In September 2014, the Company issued Convertible Notes, which provide in certain situations for the conversion of the outstanding principal amount of the Convertible Notes into shares of the Company’s common stock at a predefined conversion rate.  See Note 5, “Convertible Notes”, for additional information.  In conjunction with the issuance of the Convertible Notes, the Company entered into capped call option transactions, or Capped Calls, with certain counterparties.  The Capped Calls are expected generally to reduce the potential dilution, and/or offset, to an extent, the cash payments the Company may choose to make in excess of the principal amount, upon conversion of the Convertible Notes.

As provided by the terms of the indenture underlying the Convertible Notes, the Company has a choice to settle the conversion obligation for the Convertible Notes in cash, shares or any combination of the two.  The Company currently intends to settle the par value of the Convertible Notes in cash and any excess conversion premium in shares.  Accordingly, the par value of the Convertible Notes will not be included in the calculation of diluted net income per share, but the dilutive effect of the conversion premium will be considered in the calculation of diluted net income per share using the treasury stock method.  The share figure in the table above represents the estimated incremental shares that would be issued, after consideration of the Capped Calls, assuming conversion of all of the outstanding Convertible Notes as of March 31, 2016.