Fair Value Measurements

Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. In determining fair value, the Company uses various methods including market, income and cost approaches. Based upon these approaches, the Company often utilizes certain assumptions that market participants would use in pricing the asset or liability, including assumptions about risk and/or the risks inherent in the inputs to the valuation technique. These inputs can be readily observable, market-corroborated, or unobservable inputs. The Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. Based upon observable inputs used in the valuation techniques, the Company is required to provide information according to the fair value hierarchy. The fair value hierarchy ranks the quality and reliability of the information used to determine fair values into three broad levels as follows:



Level 1:	Valuations for assets and liabilities traded in active markets from readily available pricing sources for market transactions involving identical assets or liabilities.
Level 2:	Valuations for assets and liabilities traded in less active dealer or broker markets. Valuations are obtained from third-party pricing services for identical or similar assets or liabilities.
Level 3:	Valuations incorporate certain assumptions and projections in determining the fair value assigned to such assets or liabilities.

In instances where the determination of the fair value measurement is based upon inputs from different levels of the fair value hierarchy, the level in the fair value hierarchy within which the entire fair value measurement falls is based upon the lowest level input that is significant to the fair value measurement in its entirety. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment, and considers factors specific to the asset or liability.

The following table summarizes the Company’s financial assets and liabilities measured at fair value on a recurring basis as of December 31, 2018 and 2019 (in thousands):



	Carrying Amount as of December 31, 2018		Fair Value Measurements As of December 31, 2018
	Carrying Amount as of December 31, 2018		Level 1		Level 2		Level 3
3.25% convertible senior notes due in 2020	$	27,974	$	—	$	—	$	27,974



	Carrying Amount as of December 31, 2019		Fair Value Measurements As of December 31, 2019
	Carrying Amount as of December 31, 2019		Level 1		Level 2		Level 3
3.25% convertible senior notes due in 2020	$	—	$	—	$	—	$	—
3.25% convertible senior notes due in 2023	50,753		—		—		50,753
Preferred stock derivative liability	5,247		—		—		5,247

The following table provides a reconciliation of the beginning and ending balances of liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) (in thousands):



3.25% convertible senior notes due in 2020	Year ended December 31,
	2018			2019
Balance at January 1,	$	22,469		$	27,974
Issuance of 3.25% convertible senior notes	8,000			—
Additions	—			7,250
Loss on extinguishment of convertible senior notes	453			10,417
Extinguishment of convertible senior notes	—			(48,170		)
Change in fair value	(2,948		)	2,529
Balance at December 31,	$	27,974		$	—



3.25% convertible senior notes due 2023	Year ended December 31,
	2018		2019
Balance at January 1,	$	—	$	—
New issuance ($29.6 million face value)	—		37,916
New issuance ($8.0 million face value)	—		10,254
Change in fair value	—		2,583
Balance at December 31,	$	—	$	50,753



Preferred stock derivative liability	Year ended December 31,
	2018		2019
Balance at January 1,	$	—	$	—
New issuance of Series A Preferred Stock ($20.0 million face value)	—		4,894
Change in fair value	—		353
Balance at December 31,	$	—	$	5,247

The Company’s accounts receivable, accounts payable, term loan and accrued expenses represent financial instruments. The carrying value of these financial instruments is a reasonable approximation of fair value.

In August 2017, the Company agreed with Oasis, the holder of approximately $21.6 million face amount of its 4.25% convertible senior notes due in 2018, to extend the maturity date of these notes to November 1, 2020. In addition, the interest rate was reduced to 3.25% per annum and the conversion rate was increased to 328.0302 shares of the Company’s common stock per $1,000 principal amount of notes, among other things. These notes are hereafter referred to as the “3.25% convertible senior notes due in 2020” or “3.25% 2020 Notes.” After execution of a definitive agreement and final approval by the other members of the Company’s Board of Directors and Oasis’ Investment Committee, the transaction closed on November 7, 2017. On July 26, 2018, the Company closed a transaction with Oasis to exchange $8.0 million face amount of the 4.25% convertible senior notes due in August 2018 with convertible senior notes similar to those issued to Oasis in November 2017. The new notes mature on November 1, 2020, accrue interest at an annual rate of 3.25% and are convertible into shares of the Company’s common stock at a rate of 322.2688 shares per $1,000 principal amount of the new notes. The conversion price of the 3.25% 2020 Notes reset on November 1, 2018 to $2.54 per share and the conversion rate was increased to 393.7008 of the Company's common stock per $1,000 principal amount of notes.

In connection with the Recapitalization Transaction, the Company issued (i) amended and restated notes with respect to the $21.6 million Oasis Note issued on November 7, 2017, and the $8.0 million Oasis Note issued on July 26, 2018 (together, the “Existing Oasis Notes”), and (ii) a new $8.0 million convertible senior note having the same terms as such amended and restated notes (collectively, the “3.25% 2023 Notes”). The New Oasis Notes mature 91 days after the amounts outstanding under the New Term Loan are paid in full, and in no event later than July 3, 2023, accrue interest at an annual rate of (i) 3.25% if paid in cash or 5.00% if paid in stock plus (ii) 2.75% payable in kind. The New Oasis Notes provide, among other things, that the initial conversion price is $1.00. The conversion price will be reset on each February 9 and August 9, starting on February 9, 2020 (each, a “reset date”) to a price equal to 105% of the 5-day VWAP preceding the applicable reset date.

In connection with these transactions, the Company elected the fair value option of measurement for the 3.25% 2020 Notes and the 3.25% 2023 Notes, under ASC 815, Derivatives and Hedging. As a result, these notes are re-measured each reporting period using Level 3 inputs (Monte Carlo simulation model and inputs for stock price, risk-free rate and volatility), with changes in fair value reflected in current period earnings in its consolidated statements of operations.

The fair value of the 4.875% convertible senior notes due 2020 as of December 31, 2018 and 2019 was $93.2 million (principal amount of $113.0 million) and $1.7 million (principal amount of $1.9 million), respectively, based upon the most recent quoted market prices. The fair values of the convertible senior notes are considered to be Level 3 measurements on the fair value hierarchy.

In connection with the Recapitalization Transaction, the Company also issued 200,000 shares of Series A Preferred Stock, to the Investor Parties. The fair value of the Series A Preferred Stock derivative liability is calculated using unobservable inputs (Level 3 fair measurements). The value of the redemption provision explicitly considered the present value of the potential premium that would be paid related to, and the probability of, an event that would trigger its payment. The probability of a triggering event was based on management’s estimates of the probability of a change of control event occurring.