6. COMMON STOCK WARRANT LIABILITY

As part of the Company’s former Second Lien Credit Facility, on May 13, 2016, the Company granted the Second Lien Credit Facility lenders 1,006,568 warrants, which have an exercise price of $1.67 and expire on May 13, 2026. The warrants also provide for redemption rights, preemptive rights under certain circumstances to maintain their ownership interest in the Company, piggyback registration rights and mandatory registration rights. In addition to a refinancing, the redemption rights allow the warrant-holders, at their option, to require the Company to repurchase all or a portion of the warrants upon the occurrence of certain events, including: (i) a liquidity event, as defined in the warrant purchase agreement, or (ii) the Company’s insolvency. The repurchase value is the 21‑day average price of the Company’s common stock at the time of such liquidity event, net of the warrant exercise price. If the redemption rights are exercised, the repurchase amount is payable by the Company in cash or through the issuance of an unsecured note with a four-year term and a minimum interest rate of 13.25%, as further defined in the warrant purchase agreement, and would be guaranteed by the Company’s subsidiaries. Alternatively, the warrant-holders may choose to have the Company register and sell the shares related to the warrants through a public stock offering.

The Company’s debt refinancing of the Second Lien Credit Facility during 2018 was considered a “triggering event” for the possible redemption or registration of the warrants. The Company’s warrant-holders have not yet requested the redemption or registration of their outstanding warrants, though they may do so on any six-month anniversary of the refinancing date prior to warrant expiration. Accordingly, the obligation is reflected as a current liability.

The Company measures the fair value of the warrants at each reporting period (see Note 2). At September 30, 2019, the estimated fair value was determined using the following assumptions:  an expected contractual term of 6.62 years, an expected stock price volatility rate of 45.33%, an expected dividend yield of 0%, and an expected risk-free interest rate of 1.61%.