Net Loss Per Share

6 Months Ended

Jun. 30, 2020

Net Loss per Share

Net loss per share

Basic and diluted net loss per share attributable to common stockholders was calculated as follows:


	Three Months Ended June 30,						Six Months Ended June 30,
	2020		2019		2020		2019
Numerator:
Net loss attributable to common stockholders ($ in millions)	$	(21.0)	$	(23.1)	$	(57.5)	$	(44.7)
Denominator:
Weighted average common shares outstanding — basic and diluted	11,891,979		11,072,985		11,750,198		11,028,667
Net loss per share attributable to common stockholders — basic and diluted	$	(1.77)	$	(2.09)	$	(4.89)	$	(4.05)

The Company’s potentially dilutive securities, which include stock options and preferred stock, have been excluded from the computation of diluted net loss per share as the effect would be anti-dilutive. Therefore, the weighted average number of common shares outstanding used to calculate both basic and diluted net loss per share attributable to common stockholders is the same. The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect:


	As of June 30,
	2020	2019
Options to purchase common stock	4,578,520	2,102,124
Convertible preferred stock (as converted to common stock)	31,557,107	28,595,471
	36,135,627	30,697,595

In addition to the potentially dilutive securities noted above, in 2016 and 2017 the Company entered into stock purchase agreements with executive employees where in lieu of cash payment for the stock, promissory notes were issued (see Note 11). The Company determined the purchase of the stock to be non-substantive, and as such, the shares subject to the promissory notes would not be deemed outstanding until such time as the promissory notes have been repaid. Accordingly, the Company excluded these shares in the calculation of basic and diluted net loss per share for the three and six months ended June 30, 2019.

On June 8, 2020, all outstanding balances under the promissory notes were paid back to the Company and therefore, these shares were included in the calculation of basic and diluted net loss per share for the three and six months ended June 30, 2020.