13.Fair Value Measurements

Financial assets and liabilities and nonfinancial assets and liabilities are measured at fair value on a recurring (annual) basis under a framework of a fair value hierarchy which prioritizes the inputs into valuation techniques used to measure fair value into three broad levels. This hierarchy gives the highest priority to quoted prices (unadjusted) in active markets and the lowest priority to unobservable inputs. Further, financial assets and liabilities should be classified by level in their entirety based upon the lowest level of input that was significant to the fair value measurement. The three levels of the fair value hierarchy per ASC 820 are as follows:

Level 1: Unadjusted quoted market prices in active markets for identical assets or liabilities that are accessible at the measurement date.

Level 2: Quoted prices in inactive markets for identical assets or liabilities, quoted prices for similar assets or liabilities in active markets, or other observable inputs either directly related to the asset or liability or derived principally from corroborated observable market data.

Level 3: Unobservable inputs due to the fact that there is little or no market activity. This entails using assumptions in models which estimate what market participants would use in pricing the asset or liability.

The Company has consistently applied the valuation techniques discussed in Notes 2, 10 and 15 in all periods presented.

Recurring Fair Value Measurements

The following table summarizes the Company’s financial assets and liabilities measured on a recurring basis at fair value at December 31, 2016 and 2015 by respective level of the fair value hierarchy:


	Level 1		Level 2		Level 3		Total
	(in thousands)
At December 31, 2016
Assets:
Cash and cash equivalents	$	2,588	$	—	$	—	$	2,588
Trade accounts receivable		380		—		—		380
Short-term investments		334		—		—		334
	$	3,302	$	—	$	—	$	3,302

Liabilities:
Warrant liability - related party	$	—	$	—	$	976	$	976
Warrant liability		—		—		922		922
	$	—	$	—	$	1,898	$	1,898

At December 31, 2015
Assets:
Cash and cash equivalents	$	4,077	$	—	$	—	$	4,077
Trade accounts receivable		546		—		—		546
Short-term investments		72		—		—		72
	$	4,695	$	—	$	—	$	4,695

Liabilities:
Warrant liability - related party	$	—	$	—	$	117	$	117
Warrant liability		—		—		93		93
Derivative liability - related party		—		—		488		488
	$	—	$	—	$	698	$	698

The Company’s cash equivalents, comprised principally of U.S. treasury securities, are classified within Level 1 of the fair value hierarchy.

The Company’s trade accounts receivable are classified within Level 1 of the fair value hierarchy, are related to the sale of metals at our Velardeña Properties and the oxide plant lease and are valued at published metals prices per the terms of the refining and smelting agreements and lease rates per the plant lease agreement.

At December 31, 2016 and 2015, the Company recorded a liability for warrants to acquire the Company’s stock as a result of anti-dilution clauses in the warrant agreements that could result in a resetting of the warrant exercise price in the event the Company were to issue additional shares of its common stock in a future transaction at a price lower than the current exercise price of the warrants (see Note 15). The Company assesses the fair value of its warrant liability at the end of each reporting period, with changes in the value recorded as “Warrant derivative (loss) gain” on the Company’s Condensed Consolidated Statements of Operations and Comprehensive Loss. The valuation policies are approved by the Chief Financial Officer who reviews and approves the inputs used in the fair value calculations and the changes in fair value measurements from period to period for reasonableness. Fair value measurements are discussed with the Company’s Chief Executive Officer, as deemed appropriate. The warrant liability has been recorded at fair value as of December 31, 2016 and 2015 based primarily on a valuation performed by a third party expert using a Monte Carlo simulation, which falls within Level 3 of the fair value hierarchy. The valuation model takes into account the probability that the Company could issue additional shares in a future transaction at a lower price than the current exercise price of the warrants.

The beneficial conversion feature of the Sentient Note represents an embedded derivative as defined by ASC 815 (see Note 10). ASC 815 provides that a derivative instrument’s fair value must be bifurcated from the host contract and separately recorded on the Company’s Condensed Consolidated Balance Sheets. At December 31, 2015 and at each of the conversion dates (see Note 10), the Company had recorded a derivative liability related to the beneficial conversion feature of the Sentient Note. On June 10, 2016, the remaining Sentient Note and related embedded derivative had been fully retired. The Company assesses the fair value of the derivative liability at the end of each reporting period, with changes in the value recorded as “Derivative loss” on the Company’s Condensed Consolidated Statements of Operations and Comprehensive Loss. The valuation policies are approved by the Chief Financial Officer who reviews and approves the inputs used in the fair value calculations and the changes in fair value measurements from period to period for reasonableness. Fair value measurements are discussed with the Company’s Chief Executive Officer, as deemed appropriate. The derivative liability was recorded at fair value at December 31, 2015 and each of the conversion dates based primarily on a valuation performed by a third party expert using a Monte Carlo simulation, which falls within Level 3 of the fair value hierarchy. The valuation model takes into account, among other items: 1) the probability of successfully achieving stockholder approval of the loan’s conversion feature, 2) future variations in the Company’s stock price, and 3) the probability of entering into an equity transaction prior to the Loan maturity date that would lower the conversion price.

In addition to the warrant exercise prices (see Note 15) and Sentient Note conversion price (see Note 10) other significant inputs to the warrant valuation model and derivative valuation model included the following as applicable:



	December 31,		December 31,
	2016		2015
Company's ending stock price	$	0.58	$	0.20
Company's stock volatility		110%		85%
Applicable risk free interest rate		1.39%		1.48%

An increase or decrease in the Company’s stock price, in isolation, would result in a relatively lower or higher fair value measurement respectively. A decrease in the probability of the issuance of additional common stock at a lower price than the current warrant exercise price would result in a lower value for the warrants. The table below highlights the change in fair value of the warrant liability and the derivative liability.


	Fair Value Measurements
	Using Significant Unobservable
	Inputs (Level 3)
	Warrant Liabilities		Derivative Liability
	(in thousands)
Beginning balance at January 1, 2015	$	1,554	$	—
Sentient Note, October 27, 2015		—		1,040
Change in estimated fair value		(1,344)		(552)
Ending balance at December 31, 2015	$	210	$	488
Conversion of Sentient Loan (see Note 10)		—		(488)
Change in estimated fair value		1,688		—
Ending balance at December 31, 2016	$	1,898	$	—

Non-recurring Fair Value Measurements

There were no non-recurring fair value measurements at December 31, 2016.

The Company did conduct a fair value assessment of its mineral properties related to the Velardeña Properties at September 30, 2015 (see Note 2). The following table summarizes the Company’s non-recurring fair value measurements at September 30, 2015 by respective level of the fair value hierarchy:


	Level 1		Level 2		Level 3		Total
	(in thousands)
At September 30, 2015
Assets:
Mineral properties	$	—	$	—	$	1,354	$	1,354
	$	—	$	—	$	1,354	$	1,354

The Company assesses the fair value of its long lived assets if circumstances indicate a change in the fair value has occurred. The valuation policies are approved by the Chief Financial Officer who reviews and approves the inputs used in the fair value calculations and the changes in fair value measurements from period to period for reasonableness. Fair value measurements are discussed with the Company’s Chief Executive Officer, as deemed appropriate.

To determine the fair value of mineral properties the Company uses a discounted cash flow evaluation approach and relied on a third party mining consulting and engineering firm to assist with the determination of a residual value for the Velardeña mineral properties, which falls within Level 3 of the fair value hierarchy. The discounted cash flow valuation approach relies upon assumptions for future metals prices and projected silver and gold grades, recoveries, and mining and processing costs related to the Velardeña Properties. In determining the residual value of the mineral properties the third-party mining consulting and engineering firm reviewed comparable sales of similar properties in the region and considered the location of the Company’s properties to other active mining operations in close proximity to the Company’s properties. See Note 2 for further details related to the determination of fair value.