In connection with a debt financing in December 2013, the Company issued warrants to purchase 128,231 shares of its common stock with an exercise price of $5.84 per share. These warrants are exercisable any time at the option of the holder until December 16, 2023. None of these warrants have been exercised to date and they all remained outstanding at March 31, 2019.

In connection with the merger of the Company and ViewRay Technologies, Inc. in July 2015, or the Merger, in July and August 2015, the Company conducted a private placement offering during which the Company issued warrants, or the 2015 Placement Warrants, that provide the warrant holder the right to purchase 198,760 shares of common stock at an exercise price of $5.00 per share. The 2015 Placement Warrants are exercisable at any time at the option of the holder until the five-year anniversary of its date of issuance. Prior to March 31, 2019, the Company issued 92,487 shares of its common stock upon the net exercise of 159,010 shares of the 2015 Placement Warrants. The remaining 39,750 shares of the 2015 Placement Warrants have not been exercised and remained outstanding at March 31, 2019.

In connection with the March 2018 Direct Registered Offering, the Company issued warrants to purchase 1,418,116 shares of common stock at an exercise price of $8.31 per share, or the 2018 Offering Warrants. The 2018 Offering Warrants became exercisable upon issuance and expire in March 2025. None of the 2018 Offering Warrants have been exercised to date and they all remained outstanding at March 31, 2019.

As separate classes of securities were issued in a bundled transaction, the gross proceeds from the March 2018 Direct Registered Offering of $59.1 million was allocated to common stock, Series A convertible preferred stock and the 2018 Offering Warrants based on their respective relative fair value upon issuance. The aggregate fair value of the 2018 Offering Warrants of $7.4 million was estimated using the Black-Scholes option-pricing model with the following weighted-average assumptions: expected term of seven years, expected volatility of 62.5%, risk-free interest rate of 2.8% and expected dividend yield of 0%. The allocated proceeds from the 2018 Offering Warrants of $6.6 million was recorded in additional paid-in-capital.

In connection with private placement offerings in 2017 and 2016, the Company issued common stock warrants, or the 2017 and 2016 Placement Warrants, which contain protection whereby the warrant holders will have the right to receive cash in the amount equal to the Black-Scholes value of the warrants upon the occurrence of a Change of Control, as defined in the 2017 and 2016 Placement Warrants. The 2017 and 2016 Placement Warrants were accounted for as a liability at the date of issuance and are adjusted to fair value at each balance sheet date, with the change in fair value recorded as a component of other income (expense), net in the condensed consolidated statements of operations and comprehensive loss. The key terms of the 2017 and 2016 Placement Warrants are as follows:

	Issuance Date	Term	Exercise Price Per Share		Warrants Exercised during the Three Months Ended March 31, 2019		Warrants Outstanding at March 31, 2019
2017 Placement Warrants	January 2017	7 years	$	3.17		6,022		1,703,510
2016 Placement Warrants	August and September 2016	7 years	$	2.95		15,549		1,115,066
Total						21,571		2,818,576

During the three months ended March 31, 2019 and 2018, the Company recorded a loss of $3.0 million and a gain of $8.2 million, respectively, related to the change in fair value of the 2016 and 2017 Placement Warrants. The fair value of the 2016 and 2017 Placement Warrants at March 31, 2019 and December 31, 2018, respectively, was estimated using the Black-Scholes option-pricing model and the following weighted-average assumptions:

	2017 Placement Warrants				2016 Placement Warrants
	March 31, 2019		December 31, 2018		March 31, 2019	December 31, 2018
Expected term (in years)		4.8		5.1	4.4		4.7
Expected volatility	59.4%		60.8%		60.0%	60.9%
Risk-free interest rate	2.2%		2.5%		2.2%	2.5%
Expected dividend yield	0%		0%		0	0%