Convertible debt (Notes)

9 Months Ended

Sep. 30, 2021

Convertible Senior Notes

The following is a summary of the Company's convertible senior notes as of September 30, 2021 (in thousands):


	Date of Issuance	Unpaid Principal Balance		Net Carrying Amount				Contractual Interest Rates
				Current		Noncurrent


1% Convertible Notes due in 2024 ("2024 Notes")	May 2019	$	143,750	$	—	$	141,433	1%
2.25% Convertible Notes due in 2027 ("2027 Notes")	September 2020	$	150,000	$	—	$	146,481	2.25%

The 2027 and 2024 Notes (collectively, the "Notes") are general unsecured obligations and rank senior in right of payment to all of the Company's indebtedness that is expressly subordinated in right of payment to the Notes, rank equally in right of payment with all of the Company's existing and future liabilities that are not so subordinated, are effectively junior to any of the Company's secured indebtedness to the extent of the value of the assets securing such indebtedness and are

structurally subordinated to all indebtedness and other liabilities of the Company's subsidiaries (including trade payables but excluding intercompany obligations owed to the Company or its subsidiaries).

Interest related to the 2027 Notes is payable semiannually in arrears in cash on March 15 and September 15 of each year, beginning on March 15, 2021. Interest related to the 2024 Notes is payable semi-annually in arrears on May 15 and November 15 of each year, beginning on November 15, 2019. The 2027 Notes mature on September 15, 2027 and the 2024 Notes mature on May 15, 2024, unless redeemed or converted in accordance with their terms prior to such date.

Each $1,000 of principal of the 2027 Notes will initially be convertible into 23.9137 shares of the Company’s common stock, which is equivalent to an initial conversion price of approximately $41.82 per share. Each $1,000 of principal of the 2024 Notes will initially be convertible into 15.1394 shares of the Company’s common stock, which is equivalent to an initial conversion price of approximately $66.05 per share. The initial conversion price for the 2027 and the 2024 Notes is subject to adjustment upon the occurrence of certain specified events.

As of September 30, 2021, the 2027 and 2024 Notes are not yet convertible and their remaining term is approximately 71 months and 31 months, respectively.

As of September 30, 2021 and December 31, 2020, the fair value of the principal amount of the Notes in the aggregate was $302.2 million and $363.8 million, respectively. The estimated fair value was determined based on inputs that are observable in the market or that could be derived from, or corroborated with, observable market data, including the Company's stock price and interest rates, which represents level 2 in the fair value hierarchy.

Effective January 1, 2021, the Company early adopted ASU 2020-06, Debt - Debt with Conversion and Other Options and Derivatives and Hedging - Contracts in an Entity's Own Equity. Upon adoption of the new standard, the Company removed the debt discount and adjusted the debt issuance cost which was previously allocated between the liability and the equity component, resulting in an increase of $68.8 million to convertible debt, net. In addition, the Company recorded a reduction to additional paid-in capital of $80.1 million related to the equity conversion component of the outstanding convertible notes which was previously separated and recorded in equity. The net cumulative impact of the adoption of the standard was recorded as a decrease to accumulated deficit.

The Notes consist of the following (in thousands):


	September 30, 2021		December 31, 2020
Liability component:
Principal	$	293,750	$	293,750
Less: debt discount and issuance cost, net of amortization	(5,836)		(75,722)
Net carrying amount	$	287,914	$	218,028

Equity component(1)	$	—	$	80,098

(1) Recorded within additional paid-in capital in the unaudited condensed consolidated balance sheet. As of December 31, 2020, it included $47.2 million and $32.9 million related to the 2027 and 2024 Notes, respectively, which was net of $1.3 million and $1.1 million issuance cost in equity, respectively.

The following table sets forth total interest expense recognized related to the Notes (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Coupon interest	$	1,203	$	500	$	3,609	$	1,219
Amortization of debt issuance costs	373		174		1,119		488
Amortization of debt discount	—		1,824		—		4,938
Total	$	1,576	$	2,498	$	4,728	$	6,645

Capped Call Transactions

In September 2020 and in May 2019, in connection with the offering of the 2027 and 2024 Notes, respectively, the Company entered into privately negotiated capped call transactions (collectively, the "Capped Call") with certain option counterparties. The Capped Call transactions cover, subject to customary anti-dilution adjustments, the number of shares of the

Company’s common stock initially underlying the Notes, at a strike price that corresponds to the initial conversion price of the Notes, also subject to adjustment, and are exercisable upon conversion of the Notes. The Capped Call transactions are intended to reduce potential dilution to the Company’s common stock and/or offset any cash payments the Company will be required to make in excess of the principal amounts upon any conversion of Notes, and to effectively increase the overall conversion price of the 2027 Notes from $41.82 to $78.90 per share, and for the 2024 Notes from $66.05 to $101.62 per share. As the Capped Call transactions meet certain accounting criteria, they are recorded in stockholders’ equity and are not accounted for as derivatives. The cost of the Capped Call was $25.3 million and $16.4 million for the 2027 and 2024 Notes, respectively, and was recorded as part of additional paid-in capital.