The following table summarizes the long-term debt, net at September 30, 2021 and December 31, 2020 (in thousands):


	September 30, 2021		December 31, 2020
0.25% Convertible Senior Notes due 2028
Principal	$	345,000	$	—
Unamortized debt discount	(9,326)		—
Unamortized debt issuance costs	(216)		—
Total 0.25% Convertible Senior Notes due 2028	$	335,458	$	—

1.25% Convertible Senior Notes due 2025
Principal	$	201,250	$	201,250
Unamortized debt discount	(4,386)		(32,592)
Unamortized debt issuance costs	(543)		(538)
Total 1.25% Convertible Senior Notes due 2025	$	196,321	$	168,120

Equipment financing obligations	1,716		3,808

Total debt	$	533,495	$	171,928

Less: Current portion of equipment financing obligations	(1,564)		(2,841)
Total long-term debt, net	$	531,931	$	169,087

At September 30, 2021, the estimated fair values (Level 2) of the 0.25% Convertible Senior Notes due 2028 and the 1.25% Convertible Senior Notes due 2025 were $342.4 million and $280.3 million, respectively. There was no such estimated fair value as of December 31, 2020 related to the 0.25% Convertible Senior Notes due 2028. At December 31, 2020, the estimated fair value (Level 2) of the 1.25% Convertible Senior Notes due 2025 was $320.9 million. At September 30, 2021 and December 31, 2020, the carrying value of the Company’s equipment financing obligations approximated fair value based on the current market conditions for similar instruments.

On January 11, 2021, the Company completed the sale of $345 million of Convertible Senior Notes with a stated interest rate of 0.25% and a maturity date of January 15, 2028 (the “2028 Convertible Notes”), unless earlier converted, redeemed, or repurchased. The 2028 Convertible Notes were issued at a discounted price of 97% of their principal amount. The total net proceeds from the issuance of the 2028 Convertible Notes and exercise of the Over-allotment Option was approximately $334.4 million, which includes approximately $10.6 million of discounts, commissions and offering expenses paid by the Company. On January 11, 2021, the Company entered into an Indenture (the “Indenture”), with U.S. Bank National Association, as trustee (the “Trustee”), governing the 2028 Convertible Notes. The Company used a portion of the net proceeds from the Offerings to enter into capped call transactions (as described below under the heading “Capped Call Transactions”).

Prior to September 15, 2027, noteholders may convert their 2028 Convertible Notes at their option, only in the following circumstances: (1) during any calendar quarter commencing after the calendar quarter ending on June 30, 2021 (and only during such calendar quarter), if the last reported sale price of the common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day; (2) during the five business day period after any five consecutive trading day period in which the trading price per $1,000 principal amount of 2028 Convertible Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company’s common stock and the conversion rate on each such trading day; (3) if the Company calls any or all of the notes for redemption, at any time prior to the close of business on the scheduled trading day immediately preceding the redemption date; or (4) upon the occurrence of specified corporate events. On or after September 15, 2027 until the close of business on the second business day immediately preceding the maturity date, noteholders may convert their 2028 Convertible Notes at any time, regardless of the foregoing circumstances.

The last reported sales price of the Company’s common stock was not greater than or equal to 130% of the conversion price of the 2028 Convertible Notes on at least 20 of the last 30 consecutive trading days of the quarter ended September 30, 2021. The last reported sales price of the Company’s common stock was not greater than or equal to 130% of the conversion price of the 2028 Convertible Notes on at least 20 of the last 30 consecutive trading days of the quarter ended June 30, 2021. Based on the terms of the 2028 Convertible Notes, the holders could not have converted all or a portion of their 2028 Convertible Notes in the third quarter of 2021. When a conversion notice is received, the Company has the option to pay or deliver cash, shares of

Upon conversion, the Company will pay or deliver, as applicable, cash, shares of common stock or a combination of cash and shares of common stock, at its election. The initial conversion rate for the 2028 Convertible Notes is 15.1172 shares of common stock per $1,000 in principal amount of 2028 Convertible Notes, equivalent to an initial conversion price of approximately $66.15 per share of common stock. The conversion rate is subject to adjustment as described in the Indenture. In addition, following certain corporate events that occur prior to the maturity date as described in the Indenture, the Company will pay a make-whole premium by increasing the conversion rate for a holder who elects to convert its 2028 Convertible Notes in connection with such a corporate event in certain circumstances. The value of the 2028 Convertible Notes, if-converted, does not exceed the principal amount based on a closing stock price of $48.24 on September 30, 2021. For the three and nine months ended September 30, 2021, the Company excluded 5,215,434 and 5,100,809 shares, respectively, in diluted weighted average common shares outstanding for the if-converted impact of the 2028 Convertible Notes in the diluted net (loss) income per share calculation as the shares would have an anti-dilutive effect. For further details on the impact of the 2028 Convertible Notes on net (loss) income per share please refer to Note 12. Net (Loss) Income Per Share.

The Company may not redeem the 2028 Convertible Notes prior to January 20, 2025. The Company may redeem for cash all or any portion of the 2028 Convertible Notes, at its option, on or after January 20, 2025 if the last reported sale price of its common stock has been at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period (including the last trading day of such period) ending on, and including, the trading day immediately preceding the date of notice by the Company of redemption at a redemption price equal to 100% of the principal amount of the 2028 Convertible Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date. No sinking fund is provided for the 2028 Convertible Notes.

If an event involving bankruptcy, insolvency or reorganization events with respect to the Company occurs, then the principal amount of, and all accrued and unpaid interest on, all of the 2028 Convertible Notes then outstanding will immediately become due and payable. If any other default event occurs and is continuing, then noteholders of at least 25% of the aggregate principal amount of the 2028 Convertible Notes then outstanding, by notice to the Company, may declare the principal amount of, and all accrued and unpaid interest on, all of the 2028 Convertible Notes then outstanding to become due and payable immediately. If the Company undergoes a Fundamental Change (as defined in the Indenture), then noteholders may require the Company to repurchase their 2028 Convertible Notes at a cash repurchase price equal to the principal amount of the 2028 Convertible Notes to be repurchased, plus accrued and unpaid interest, if any, to, but excluding, the Fundamental Change Repurchase Date (as defined in the Indenture).

The 2028 Convertible Notes are the Company’s senior, unsecured obligations and will be equal in right of payment with its existing and future senior, unsecured indebtedness, senior in right of payment to its existing and future indebtedness that is expressly subordinated to the 2028 Convertible Notes and effectively junior to its existing and future secured indebtedness, to the extent of the value of the collateral securing that indebtedness. The 2028 Convertible Notes will be structurally subordinated to all existing and future indebtedness and other liabilities, including trade payables, of its subsidiaries.

The interest expense recognized on the 2028 Convertible Notes includes $0.2 million, $0.4 million and $8,400 for the contractual coupon interest, the amortization of the debt discount and the amortization of the debt issuance costs, respectively, for the three months ended September 30, 2021. The interest expense recognized on the 2028 Convertible Notes includes $0.6 million, $1 million and $23,700 for the contractual coupon interest, the amortization of the debt discount and the amortization of the debt issuance costs, respectively, for the nine months ended September 30, 2021. There were no such amounts for the three and nine months ended September 30, 2020. The effective interest rate on the 2028 Convertible Notes is 0.70%, which includes the interest on the 2028 Convertible Notes and amortization of the debt discount and debt issuance costs. The 2028 Convertible Notes bear interest at a rate of 0.25% per annum, payable semi-annually in arrears on January 15 and July 15 of each year, beginning on July 15, 2021.

In connection with the 2028 Convertible Notes offering, on January 11, 2021, the Company entered into separate, privately negotiated convertible note hedge transactions (collectively, the “Capped Call Transactions”) with option counterparties pursuant to capped call confirmations at a cost of approximately $29.3 million. As the Capped Call Transactions meet certain accounting criteria, the Capped Call Transactions were classified as equity, are not accounted for as derivatives and were recorded as a reduction of the Company’s additional paid-in capital in the accompanying unaudited Consolidated Financial Statements. The Capped Call Transactions are not part of the terms of the 2028 Convertible Notes and will not affect any holders’ rights under the 2028 Convertible Notes. The Capped Call Transactions cover, subject to customary anti-dilution adjustments, the number of shares of the Company’s common stock that initially underlie the 2028 Convertible Notes. The number of shares underlying the Capped Call Transactions is 5.2 million.

On May 4, 2020, the Company completed the sale of $201.3 million of Convertible Senior Notes with a stated interest rate of 1.25% and a maturity date of May 1, 2025 (the “2025 Convertible Notes”), unless earlier converted, redeemed, or repurchased. The 2025 Convertible Notes were issued at a discounted price of 97% of their principal amount. The total net proceeds from the issuance of the 2025 Convertible Notes and exercise of the Over-allotment Option was approximately $194.5 million, which includes approximately $6.9 million of discounts, commissions and offering expenses paid by the Company. On May 4, 2020, the Company entered into an Indenture (the “Indenture”), with U.S. Bank National Association, as trustee (the “Trustee”), governing the 2025 Convertible Notes.

Prior to February 1, 2025, noteholders may convert their 2025 Convertible Notes at their option, only in the following circumstances: (1) during any calendar quarter commencing after the calendar quarter ending on September 30, 2020 (and only during such calendar quarter), if the last reported sale price of the common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day; (2) during the five business day period after any five consecutive trading day period in which the trading price per $1,000 principal amount of 2025 Convertible Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company’s common stock and the conversion rate on each such trading day; (3) if the Company calls any or all of the notes for redemption, at any time prior to the close of business on the scheduled trading day immediately preceding the redemption date; or (4) upon the occurrence of specified corporate events. On or after February 1, 2025 until the close of business on the business day immediately preceding the maturity date, noteholders may convert their 2025 Convertible Notes at any time, regardless of the foregoing circumstances.

The last reported sales price of the Company’s common stock was not greater than or equal to 130% of the conversion price of the 2025 Convertible Notes on at least 20 of the last 30 consecutive trading days of the quarter ended September 30, 2021. The last reported sales price of the Company’s common stock was not greater than or equal to 130% of the conversion price of the 2025 Convertible Notes on at least 20 of the last 30 consecutive trading days of the quarter ended June 30, 2021. Based on the terms of the 2025 Convertible Notes, the holders could not have converted all or a portion of their 2025 Convertible Notes in the third quarter of 2021. When a conversion notice is received, the Company has the option to pay or deliver cash, shares of the Company’s common stock, or a combination thereof. As the Company is not required to settle the 2025 Convertible Notes in cash, the 2025 Convertible Notes are classified as long-term debt as of September 30, 2021 and December 31, 2020. As of September 30, 2021, the Company had not received any conversion notices.

Upon conversion, the Company will pay or deliver, as applicable, cash, shares of common stock or a combination of cash and shares of common stock, at its election. The initial conversion rate for the 2025 Convertible Notes is 27.5198 shares of common stock per $1,000 in principal amounts of 2025 Convertible Notes, equivalent to an initial conversion price of approximately $36.34 per share of common stock. The conversion rate is subject to adjustment as described in the Indenture. In addition, following certain corporate events that occur prior to the maturity date as described in the Indenture, the Company will pay a make-whole premium by increasing the conversion rate for a holder who elects to convert its 2025 Convertible Notes in connection with such a corporate event in certain circumstances. The value of the 2025 Convertible Notes, if-converted, exceeds the principal amount by $65.9 million based on a closing stock price of $48.24 on September 30, 2021. For the three and nine months ended September 30, 2021, the Company excluded 5,538,360 shares in diluted weighted average common shares outstanding for the if-converted impact of the 2025 Convertible Notes in the diluted net (loss) income per share calculation as the shares would have an anti-dilutive effect. For the three months ended September 30, 2020, the Company included 5,538,360 shares in diluted weighted average common shares outstanding for the if-converted impact of the 2025 Convertible Notes in the diluted net (loss) income per share calculation as the shares would have a dilutive effect. For the nine months ended September 30, 2020, the Company excluded 3,112,801 shares, respectively, in diluted weighted average common shares outstanding for the if-converted impact of the 2025 Convertible Notes in the diluted net (loss) income per share calculation as the shares would have an anti-dilutive effect. For further details on the impact of the 2025 Convertible Notes on net (loss) income per share please refer to Note 12. Net (Loss) Income Per Share.

has been at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period (including the last trading day of such period) ending on, and including, the trading day immediately preceding the date of notice by the Company of redemption at a redemption price equal to 100% of the principal amount of the 2025 Convertible Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date. No sinking fund is provided for the 2025 Convertible Notes.

If an event involving bankruptcy, insolvency or reorganization events with respect to the Company occurs, then the principal amount of, and all accrued and unpaid interest on, all of the 2025 Convertible Notes then outstanding will immediately become due and payable. If any other default event occurs and is continuing, then noteholders of at least 25% of the aggregate principal amount of the 2025 Convertible Notes then outstanding, by notice to the Company, may declare the principal amount of, and all accrued and unpaid interest on, all of the 2025 Convertible Notes then outstanding to become due and payable immediately. If the Company undergoes a Fundamental Change (as defined in the Indenture), then noteholders may require the Company to repurchase their 2025 Convertible Notes at a cash repurchase price equal to the principal amount of the 2025 Convertible Notes to be repurchased, plus accrued and unpaid interest, if any, to, but excluding, the Fundamental Change Repurchase Date (as defined in the Indenture).

The 2025 Convertible Notes are the Company’s senior, unsecured obligations and will be equal in right of payment with its existing and future senior, unsecured indebtedness, senior in right of payment to its existing and future indebtedness that is expressly subordinated to the 2025 Convertible Notes and effectively junior to its existing and future secured indebtedness, to the extent of the value of the collateral securing that indebtedness. The 2025 Convertible Notes will be structurally subordinated to all existing and future indebtedness and other liabilities, including trade payables, of its subsidiaries.

The interest expense recognized on the 2025 Convertible Notes includes $0.6 million, $0.3 million and $36,500 for the contractual coupon interest, the amortization of the debt discount and the amortization of the debt issuance costs, respectively, for the three months ended September 30, 2021. The interest expense recognized on the 2025 Convertible Notes includes $1.9 million, $0.9 million and $0.1 million for the contractual coupon interest, the amortization of the debt discount and the amortization of the debt issuance costs, respectively, for the nine months ended September 30, 2021. The interest expense recognized on the 2025 Convertible Notes included $0.6 million, $1.8 million and $25,600 for the contractual coupon interest, the accretion of the debt discount and the amortization of the debt issuance costs, respectively, for the three months ended September 30, 2020. The interest expense recognized on the 2025 Convertible Notes includes $1 million, $2.7 million and $44,700, for the contractual coupon interest, the amortization of the debt discount and the amortization of the debt issuance costs, respectively, for the nine months ended September 30, 2020. The effective interest rate on the 2025 Convertible Notes is 1.96%, which includes the interest on the 2025 Convertible Notes and amortization of the debt discount and debt issuance costs. The 2025 Convertible Notes bear interest at a rate of 1.25% per annum, payable semi-annually in arrears on May 1 and November 1 of each year, which began on November 1, 2020.

Maturities of long-term debt as of September 30, 2021 are summarized as follows (in thousands):


	0.25% Convertible Senior Notes		1.25% Convertible Senior Notes		Equipment Financing Obligations		Total Debt
Remainder of 2021	$	—	$	—	$	716	$	716
2022	—		—		930		930
2023	—		—		69		69
2024	—		—		1		1
2025	—		201,250		—		201,250


Thereafter	345,000		—		—		345,000
Total Debt	$	345,000	$	201,250	$	1,716	$	547,966
Less: Current portion of long-term debt	—		—		(1,564)		(1,564)
Less: Unamortized debt discount	(9,326)		(4,386)		—		(13,712)
Less: Unamortized debt issuance costs	(216)		(543)		—		(759)
Long-term debt, net	$	335,458	$	196,321	$	152	$	531,931