From time to time, the Company issues warrants to its investors, creditors and various other individuals. The Company’s outstanding common stock warrants that are classified as equity warrants are included as a component of stockholder’s equity at the date of grant at the relative fair value at that grant date. Common stock warrants accounted for as liabilities are included in non-current liabilities. The warrants have an exercise price ranging from $0.55 to $694.80 per share and generally expire between five and ten years after the date of issuance. The Company had common stock warrants outstanding of 9,213,008 and 7,181,741, at June 30, 2022 and December 31, 2021, respectively.

On January 31, 2022, the Company and the Investor entered into the January 2022 Waiver Agreement (See Note 4, Fair Value Measurements). In addition to irrevocably waiving any adjustment to the exercise price of the Senior Secured Promissory Note Warrants and the May 2021 Warrants held by the Investor from and after the Effective Date for the Company's issuances of equity or equity-linked securities at a price below the exercise price of the warrants, the January 2022 Waiver Agreement also includes agreement by the parties to, among other things, (i) restrict the Investor's ability to sell the Company's securities through a "leak out" provision whereby sales are restricted by applying a volume limitation, (ii) shorten the notice period for the Investor’s participation rights related to certain future securities offerings, (iii) restrict the Company’s ability to conduct a primary offering of its securities for a specified period of time, and (iv) provide registration rights for the shares underlying the January 2022 Warrant.

As consideration for the foregoing, pursuant to the January 2022 Waiver Agreement, the Company issued the Investor the January 2022 Warrant. The January 2022 Warrant is exercisable beginning six months following the Effective Date. The exercise price for the January 2022 Warrant is $1.10 (the closing price of the Company’s common stock on January 28, 2022), subject to customary adjustments for stock splits, stock dividends, stock combinations, reclassifications and similar transactions.

In the three months ended March 31, 2022, the Investor exchanged the remaining 3,994,302 May 2021 warrants into shares of the Company’s common stock in cashless exercises. Following these exercises, the May 2021 Warrants were fully exercised. As of June 30, 2022, there are no May 2021 Warrants outstanding.

In connection with the May 2022 Registered Direct Offering (see Note 5, Stockholders' Equity), the Company issued the May 2022 Purchase Warrants. The May 2022 Purchase Warrants are not exercisable until six months following the date of issuance and expire five and a half years from the date of issuance. The May 2022 Purchase Warrants were classified as equity. Concurrently, the Company issued the May 2022 Placement Agent Warrants. The May 2022 Placement Agent Warrants are not exercisable until six months following the date of issuance and expire five years from the date of issuance.

The following table summarizes warrant activity for the six months ended June 30, 2022:


	Number of Warrants			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)
Warrants outstanding, December 31, 2021		7,181,741		$	5.96		4.45
Granted		6,115,491		$	0.85		5.24
Exercised		(3,994,302	)	$	3.88		4.11
Forfeited, expired or cancelled		(89,922	)	$	80.72		—
Warrants outstanding, June 30, 2022		9,213,008		$	2.74		4.79