4. Net Loss per Share

Basic net loss per share is computed by dividing net loss by the weighted average number of shares of common stock outstanding for the period. The Company’s potentially dilutive shares, which include outstanding common stock options, unvested restricted stock and preferred stock, have not been included in the computation of diluted net loss per share for any of the periods presented as the result would be anti-dilutive. Such potentially dilutive shares of common stock at June 30, 2018 and 2017 consisted of the following:


	June 30,
	2018		2017
Stock options		4,303,802		3,537,835
Unvested restricted stock		1,198,868		1,330,492
Preferred stock		41,754,054		23,289,258

		47,256,724		28,157,585

The Series 1 preferred stock automatically converts into shares of common stock upon the date the first approval in the United States of (i) a Ziopharm Product, as defined in and developed under the Exclusive Channel Partner Agreement dated as of January 6, 2011 and as amended from time to time, by and between the Company and Intrexon, or (ii) a Product, as defined in and developed under the Exclusive Channel Collaboration Agreement dated September 28, 2015 and as amended from time to time, by and between the Company and Intrexon, or (iii) a Product as defined in and developed under the License and Collaboration Agreement dated March 27, 2015 and as amended from time to time, by and among Intrexon, Ares Trading, S.A. and the Company, is publicly announced. Assuming a conversion event date of June 30, 2018, the Series 1 preferred stock would convert into 41,754,054 shares of common stock using the greater of (i) the volume weighted average closing price of the Company’s Common Stock as reported by the Nasdaq Stock Market, LLC over the previous 20 trading days ending on the conversion event date or (ii) $1.00 per share. See Note 6 and Note 9 for additional disclosure regarding the 2016 ECP Amendment and 2016 GvHD Amendment, valuation methodology and significant assumptions.