In conjunction with the funding of Tranche 1 and Tranche 2 under the 2019 Term Loan, the Company issued the 2019 Initial Warrant to purchase 29,514 shares of its Series C redeemable convertible preferred stock (see Note 5). The 2019 Initial Warrant is immediately exercisable, at an exercise price per share of $9.49, and expires 10 years from their date of issuance. The 2019 Initial Warrant will be automatically exercised upon the consummation or effective date of a change of control of the Company. Further, depending on the funding of the 2019 Term Loan Tranche 3, the Company was obligated to issue the 2019 Additional Warrant to the Lender to purchase up to 12,649 shares of Series C redeemable convertible preferred stock at the respective exercise price.

The estimated fair value of the 2019 Warrants on the date of issuance was $0.2 million. As of the issuance date, the fair value of the 2019 Warrants was calculated using the Black-Scholes option-pricing model and was based on a term of 10 years, a risk-free interest rate of 2.99%, expected volatility of 50.95%, and 0% expected dividend yield.

At initial recognition, the 2019 Warrants were recorded at their estimated fair values and were subject to remeasurement at each balance sheet date, with changes in fair value recognized as a component of net income. As of December 31, 2020 and June 30, 2021, the estimated fair values of the 2019 Warrants were $0.3 million and $1.0 million, respectively. The fair value of the 2019 Warrants as of December 31, 2020 was calculated using the Black-Scholes option-pricing model with the following assumptions:


		December 31,
		2020
Expected term (in years)		8.1 – 8.5
Expected volatility		42.18% – 42.63%
Risk-free interest rate		2.33% – 2.49%
Dividend yield		–

The fair value of the 2019 Warrants as of June 30, 2021 was calculated using a multi-scenario Option- Pricing Method with Discounts for Lack of Marketability for each class of security.

As of June 30, 2021, the 2019 Initial Warrant remained outstanding and the remaining term was 7.8 years. The 2019 Additional Warrant of 12,649 shares of series C redeemable convertible preferred stock was not legally issued and expired upon modification of the 2019 Term Loan.

In conjunction with entering the 2020 Term Loan agreement, the Company issued the 2020 Warrant to purchase 300,000 shares of its Series F redeemable convertible preferred stock (see Note 5). The 2020 Warrant is immediately exercisable, at an exercise price per share of $21.88, and expires 10 years from its date of issuance. The warrant will be automatically exercised upon the consummation or effective date of a change of control of the Company.

The estimated fair value of the 2020 Warrant on the date of issuance was $1.8 million. As of the issuance date, the fair value of the 2020 Warrant was calculated using a multi-scenario Method with Discounts for Lack of Marketability for each class of security.

At initial recognition, the 2020 Warrant was recorded at its estimated fair values and was subject to remeasurement at each balance sheet date, with changes in fair value recognized as a component of net income. As of June 30, 2021 and December 31, 2020, the estimated fair values of the 2020 Warrant was $6.0 million and $1.8 million, respectively. The fair value of the 2020 Warrant as of June 30, 2021 and December 31, 2020 was calculated using a multi-scenario Method with Discounts for Lack of Marketability for each class of security.

As of June 30, 2021, the 2020 Warrant remained outstanding and the remaining term was 9.4 years.

The fair value of the redeemable convertible preferred stock warrants was determined using the following assumption as of each report date:


	June 30,	December 31,
	2021	2020
Term (in years)	0.04 – 2.04	0.58 – 2.58
Expected volatility	37.9% - 59.5%	55.9% - 65.6%
Risk-free interest rate	0.05% - 0.26%	0.08% - 0.18%