
	June 30, 2021		December 31, 2020
	(In thousands)
Convertible notes
Notes due 2028	$	575,000	$	—
Less: unamortized discount and issuance costs	(159,801)		—
Carrying amount of Notes due 2028	415,199		—

Notes due 2026	632,500		—
Less: unamortized discount and issuance costs	(123,602)		—
Carrying amount of Notes due 2026	508,898		—

Notes due 2025	102,175		320,000
Less: unamortized discount and issuance costs	(18,475)		(64,979)
Carrying amount of Notes due 2025	83,700		255,021

Notes due 2024	1,068		88,140
Less: unamortized discount and issuance costs	(201)		(19,119)
Carrying amount of Notes due 2024	867		69,021

Notes due 2023	5,000		5,000
Less: unamortized issuance costs	(82)		(102)
Carrying amount of Notes due 2023	4,918		4,898

Sale of long-term financing receivable recorded as debt	558		1,925


Total carrying amount of debt	1,014,140		330,865

Less: current portion of convertible notes and long-term financing receivable recorded as debt	(85,125)		(325,967)
Long-term debt	$	929,015	$	4,898

On March 1, 2021, the Company issued $575 million aggregate principal amount of 0.0% convertible senior notes due 2028 (the “Notes due 2028”). The Notes due 2028 will not bear regular interest, and the principal amount of the Notes due 2028 will not accrete. The Notes due 2028 are general unsecured obligations and are governed by an indenture between the Company and U.S. Bank National Association, as trustee. The Notes due 2028 will mature on March 1, 2028, unless earlier repurchased by the Company or converted at the option of the holders. The Company received approximately $566.4 million in net proceeds, after deducting the initial purchasers’ discount, from the issuance of the Notes due 2028.

The initial conversion rate for the Notes due 2028 is 3.5104 shares of common stock per $1,000 principal amount of the Notes due 2028 (which represents an initial conversion price of approximately $284.87 per share). The conversion rate for the Notes due 2028 will be subject to adjustment upon the occurrence of certain specified events but will not be adjusted for any accrued and unpaid special interest, if any. In addition, if a make-whole fundamental change or a redemption with respect to the Notes due 2028 occurs prior to the maturity date, under certain circumstances as specified in the relevant indenture, the Company will increase the conversion rate for the Notes due 2028 by a number of additional shares of the Company’s common stock for a holder that elects to convert its notes in connection with such make-whole fundamental change or redemption. Upon conversion, the Company will settle conversions of the Notes due 2028 through payment or delivery, as the case may be, of cash, shares of its common stock or a combination of cash and shares of its common stock, at the Company’s election.

The Company may not redeem the Notes due 2028 prior to September 6, 2024. The Company may redeem for cash all or any portion of the Notes due 2028, at the Company’s election, on or after September 6, 2024, if the last reported sale price of the Company’s common stock has been greater than or equal to 130% of the conversion price then in effect for the Notes due 2028 (i.e. $370.33, which is 130% of the current conversion price for the Notes due 2028) for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period ending on, and including, the trading day immediately preceding the date on which the Company provides notice of redemption. The redemption price will equal 100% of the principal amount of the Notes due 2028 to be redeemed, plus accrued and unpaid special interest, if any to, but excluding, the relevant redemption date. No sinking fund is provided for the Notes due 2028.

The Notes due 2028 may be converted on any day prior to the close of business on the business day immediately preceding September 1, 2027, in multiples of $1,000 principal amount, at the option of the holder only under any of 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 Company’s 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 for the Notes due 2028 (i.e., $370.33 which is 130% of the current conversion price for the Notes due 2028) on each applicable trading day; (2) during the five business day period after any five consecutive trading day period (the “measurement period”) in which the “trading price” (as defined in the relevant indenture) per $1,000 principal amount of 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 for the Notes due 2028 on each such trading day; (3) if the Company calls any or all of the Notes due 2028 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 and after September 1, 2027 until the close of business on the second scheduled trading day immediately preceding the maturity date of March 1, 2028, holders of the Notes due 2028 may convert their notes at any time, regardless of the foregoing circumstances. Upon the occurrence of a fundamental change (as defined in the relevant indenture), holders may require the Company to repurchase all or a portion of their Notes due 2028 for cash at a price equal to 100% of the principal amount of the notes to be repurchased plus any accrued and unpaid special interest, if any, to, but excluding, the fundamental change repurchase date.

In accounting for the issuance of the Notes due 2028 on March 1, 2021, the Company separated the Notes due 2028 into liability and equity components. The carrying amount of the liability component of approximately $415.0 million was calculated by using a discount rate of 4.77%, which was the Company’s borrowing rate on the date of the issuance of the Notes due 2028 for a similar debt instrument without the conversion feature. The carrying amount of the equity component of approximately $160.0 million, representing the conversion option, was determined by deducting the fair value of the liability component from the par value of the Notes due 2028. The equity component of the Notes due 2028 is included in additional paid-in capital in the condensed consolidated balance sheet and is not remeasured as long as it continues to meet the conditions for equity classification. The difference between the principal amount of the Notes due 2028 and the liability component (the “debt discount”) is amortized to interest expense using the effective interest method over the term of the Notes due 2028.

Debt issuance costs for the issuance of the Notes due 2028 were approximately $9.1 million, consisting of initial purchasers' discount and other issuance costs. In accounting for the transaction costs, the Company allocated the total amount incurred to the liability and equity components using the same proportions as the proceeds from the Notes due 2028. Transaction costs attributable to the liability component were approximately $6.6 million, which were recorded as debt issuance cost (presented as contra debt in the condensed consolidated balance sheet) and are being amortized to interest expense over the term of the Notes due 2028. The transaction costs attributable to the equity component were approximately $2.5 million and were netted with the equity component in stockholders’ equity. As of June 30, 2021, the unamortized deferred issuance cost for the Notes due 2028 was $6.2 million on the condensed consolidated balance sheet.

In connection with the offering of the Notes due 2028, the Company entered into privately-negotiated convertible note hedge transactions (“Notes due 2028 Hedge”) pursuant to which the Company has the option to purchase a total of approximately 2.0 million shares of its common stock (subject to anti-dilution adjustments), which is the same number of shares initially issuable upon conversion of the Notes due 2028, at a price of $284.87 per share, which is the initial conversion price of the Notes due 2028. The total cost of the convertible note hedge transactions was approximately $161.6 million. The convertible note hedge transactions are expected generally to reduce potential dilution to the Company’s common stock upon any conversion of the Notes due 2028 and/or offset any cash payments the Company is required to make in excess of the principal amount of converted notes, as the case may be.

Additionally, the Company separately entered into privately-negotiated warrant transactions (the “2028 Warrants”) whereby the Company sold warrants to acquire approximately 2.0 million shares of the Company’s common stock (subject to anti-dilution adjustments) at an initial strike price of $397.91 per share. The Company received aggregate proceeds of approximately $123.4 million from the sale of the Warrants. If the market value per share of the Company’s common stock, as measured under the 2028 Warrants, exceeds the strike price of the 2028 Warrants, the 2028 Warrants will have a dilutive effect on the Company’s earnings per share, unless the Company elects, subject to certain conditions, to settle the 2028 Warrants in cash. Taken together, the purchase of the Notes due 2028 Hedge and the sale of the 2028 Warrants are intended to reduce potential dilution from the conversion of the Notes due 2028 and to effectively increase the overall conversion price from $284.87 to $397.91 per share. The 2028 Warrants are only exercisable on the applicable expiration dates in accordance with the Notes due 2028 Hedge. Subject to the other terms of the Warrants, the first expiration date applicable to the Notes due 2028 Hedge is June 1, 2028, and the final expiration date applicable to the Notes due 2028 Hedge is July 27, 2028.

On March 1, 2021, the Company issued $575.0 million aggregate principal amount of 0.0% convertible senior notes due 2026 (the “Notes due 2026”). In addition, on March 12, 2021, the Company issued an additional $57.5 million aggregate principal amount of the Notes due 2026 pursuant to the initial purchasers’ full exercise of the over-allotment option for additional Notes due 2026. The Notes due 2026 will not bear regular interest, and the principal amount of the Notes due 2026 will not accrete. The Notes due 2026 are general unsecured obligations and are governed by an indenture between the Company and U.S. Bank National Association, as trustee. The Notes due 2026 will mature on March 1, 2026, unless earlier repurchased by the Company or converted at the option of the holders. The Company received approximately $623.0 million in net proceeds, after deducting the initial purchasers’ discount, from the issuance of the Notes due 2026.

The initial conversion rate for the Notes due 2026 is 3.2523 shares of common stock per $1,000 principal amount of the Notes due 2026 (which represents an initial conversion price of approximately $307.47 per share). The conversion rate for the Notes due 2026 will be subject to adjustment upon the occurrence of certain specified events but will not be adjusted for accrued and unpaid interest. In addition, if a make-whole fundamental change or a redemption with respect to the Notes due 2026 occurs prior to the maturity date, under certain circumstances as specified in the relevant indenture, the Company will increase the conversion rate for the Notes due 2026 by a number of additional shares of the Company’s common stock for a holder that elects to convert its notes in connection with such make-whole fundamental change or redemption. Upon conversion, the Company will settle conversions of Notes due 2026 through payment or delivery, as the case may be, of cash, shares of its common stock or a combination of cash and shares of its common stock, at the Company’s election.

The Company may not redeem the Notes due 2026 prior to the September 6, 2023. The Company may redeem for cash all or any portion of the Notes due 2026, at the Company’s election, on or after September 6, 2023, if the last reported sale price of the Company’s common stock has been greater than or equal to 130% of the conversion price then in effect for the Notes due 2026 (i.e., $399.71, which is 130% of the current conversion price for the Notes due 2026) for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading day period ending on, and including, the trading day immediately preceding the date on which the Company provides notice of redemption. The redemption price will equal 100% of the principal amount of the Notes due 2026 to be redeemed, plus accrued and unpaid special interest, if any, to, but excluding, the relevant redemption date for the Notes due 2026. The redemption price will be increased as described in the relevant indentures by a number of additional shares of the Company in connection with such optional redemption by the Company. No sinking fund is provided for the Notes due 2026.

The Notes due 2026 may be converted on any day prior to the close of business on the business day immediately preceding September 1, 2025, in multiples of $1,000 principal amount, at the option of the holder only under any of 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 Company’s 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 of the Notes due 2026 (i.e., $399.71, which is 130% of the current conversion price for the Notes due 2026) on each applicable trading day; (2) during the five business day period after any five consecutive trading day period (the “measurement period”) in which the “trading price” (as defined in the relevant indenture) per $1,000 principal amount of 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 for Notes due 2026 on each such trading day; (3) if the Company calls any or all of the Notes due 2026 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 and after June 30, 2021 until the close of business on the second scheduled trading day immediately preceding the maturity date of March 1, 2026, holders of the Notes due 2026 may convert their notes at any time, regardless of the foregoing circumstances. Upon the occurrence of a fundamental change (as defined in the relevant indenture), holders may require the Company to repurchase all or a portion of their Notes due 2026 for cash at a price equal to 100% of the principal amount of the notes to be repurchased plus any accrued and unpaid special interest, if any, to, but excluding, the fundamental change repurchase date.

In accounting for the issuance of the Notes due 2026 on March 1, 2021, the Company separated the Notes due 2026 into liability and equity components. The carrying amount of the liability component of approximately $509.0 million was calculated by using a discount rate of 4.44%, which was the Company’s borrowing rate on the date of the issuance of the Notes due 2026 for a similar debt instrument without the conversion feature. The carrying amount of the equity component of approximately $123.5 million, representing the conversion option, was determined by deducting the fair value of the liability component from the par value of the Notes due 2026. The equity component of the Notes due 2026 is included in additional paid-in capital in the condensed consolidated balance sheet and is not remeasured as long as it continues to meet the conditions for equity classification. The difference between the principal amount of the Notes due 2026 and the liability component (the “debt discount”) is amortized to interest expense using the effective interest method over the term of the Notes due 2026.

Debt issuance costs for the issuance of the Notes due 2026 were approximately $10.0 million, consisting of initial purchasers' discount and other issuance costs. In accounting for the transaction costs, the Company allocated the total amount incurred to the liability and equity components using the same proportions as the proceeds from the Notes due 2026. Transaction costs attributable to the liability component were approximately $8.0 million, which were recorded as debt issuance cost (presented as contra debt in the condensed consolidated balance sheet) and are being amortized to interest expense over the term of the Notes due 2026. The transaction costs attributable to the equity component were approximately $2.0 million and were netted with the equity component in stockholders’ equity. As of June 30, 2021, the unamortized deferred issuance cost for the Notes due 2026 was $7.5 million on the condensed consolidated balance sheet.

In connection with the offering of the Notes due 2026 (including in connection with the issuance of additional Notes due 2026 upon the initial purchasers’ exercise of their over-allotment option), the Company entered into privately-negotiated convertible note hedge transactions (the “Notes due 2026 Hedge”) pursuant to which the Company has the option to purchase a total of approximately 2.1 million shares of its common stock (subject to anti-dilution adjustments), which is the same number of shares initially issuable upon conversion of the Notes due 2026, at a price of $307.47 per share, which is the initial conversion price of the Notes due 2026. The total cost of the Notes due 2026 Hedge was approximately $124.6 million. The Notes due 2026 Hedge are expected generally to reduce potential dilution to the Company’s common stock upon any conversion of the Notes due 2026 and/or offset any cash payments the Company is required to make in excess of the principal amount of converted notes, as the case may be.

Additionally, the Company separately entered into privately-negotiated warrant transactions, including in connection with the issuance of additional Notes due 2026 upon the initial purchasers’ exercise of their over-allotment option (the “2026 Warrants”), whereby the Company sold warrants to acquire approximately 2.1 million shares of the Company’s common stock (subject to anti-dilution adjustments) at an initial strike price of $397.91 per share. The Company received aggregate proceeds of approximately $97.4 million from the sale of the 2026 Warrants. If the market value per share of the Company’s common stock, as measured under the 2026 Warrants, exceeds the strike price of the Warrants, the 2026 Warrants will have a dilutive effect on the Company’s earnings per share, unless the Company elects, subject to certain conditions, to settle the 2026 Warrants in cash. Taken together, the purchase of the Notes due 2026 Hedge and the sale of the 2026 Warrants are intended to reduce potential dilution from the conversion of the Notes due 2026 and to effectively increase the overall conversion price from $307.47 to $397.91 per share. The 2026 Warrants are only exercisable on the applicable expiration dates in accordance with the 2026 Warrants. Subject to the other terms of the 2026 Warrants, the first expiration date applicable to the Warrants is June 1, 2026, and the final expiration date applicable to the 2026 Warrants is July 27, 2026.

On March 9, 2020, the Company issued $320.0 million aggregate principal amount of the Notes due 2025 (the “Notes due 2025”). The Notes due 2025 are general unsecured obligations and bear interest at an annual rate of 0.25% per year, payable semi-annually on March 1 and September 1 of each year, beginning September 1, 2020. The Notes due 2025 are governed by an indenture between the Company and U.S. Bank National Association, as trustee. The Notes due 2025 will mature on March 1, 2025, unless earlier repurchased by the Company or converted at the option of the holders. The Company may not redeem the notes prior to the maturity date, and no sinking fund is provided for the notes. The Notes due 2025 may be converted, under certain circumstances as described below, based on an initial conversion rate of 12.2637 shares of common stock per $1,000 principal amount (which represents an initial conversion price of $81.54 per share). The conversion rate for the Notes due 2025 will be subject to adjustment upon the occurrence of certain specified events but will not be adjusted for accrued and unpaid interest. In addition, upon the occurrence of a make-whole fundamental change (as defined in the relevant indenture), the Company will, in certain circumstances, increase the conversion rate by a number of additional shares for a holder that elects to convert its notes in connection with such make-whole fundamental change. The Company received approximately $313.0 million in net proceeds, after deducting the initial purchasers’ discount, from the issuance of the Notes due 2025.

The Notes due 2025 may be converted prior to the close of business on the business day immediately preceding September 1, 2024, in multiples of $1,000 principal amount, at the option of the holder only under the following circumstances: (1) during any calendar quarter commencing after the calendar quarter ending on June 30, 2020 (and only during such calendar quarter), if the last reported sale price of the Company’s 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 (the “measurement period”) in which the “trading price” (as defined in the relevant indenture) per $1,000 principal amount of 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; or (3) upon the occurrence of specified corporate events. On and after September 1, 2024 until the close of business on the second scheduled trading day immediately preceding the maturity date of March 1, 2025, holders may convert their notes at any time, regardless of the foregoing circumstances. Upon the occurrence of a fundamental change (as defined in the relevant indenture), holders may require the Company to repurchase all or a portion of their Notes due 2025 for cash at a price equal to 100% of the principal amount of the notes to be repurchased plus any accrued and unpaid interest to, but excluding, the fundamental change repurchase date.

As of June 30, 2021, the sale price of the Company’s common stock was greater than or equal to $106.00 (130% of the notes conversion price) for at least 20 trading days (whether consecutive or not) during a period of 30 consecutive trading days preceding the quarter-ended June 30, 2021. As a result, as of July 1, 2021, the Notes due 2025 are convertible at the holders’ option through September 30, 2021. Accordingly, the Company classified the net carrying amount of the Notes due 2025 of $102.2 million as Debt, current on the condensed consolidated balance sheet as of June 30, 2021. From July 1, 2021 through the date this Quarterly Report on Form 10-Q is available to be issued, the Company has not received any requests for conversion of the Notes due 2025.

For the period from March 9, 2020, the issuance date, through May 19, 2020, the number of authorized and unissued shares of the Company’s common stock that are not reserved for other purposes was less than the maximum number of underlying shares that would be required to settle the Notes due 2025 into equity. Accordingly, unless and until the Company had a number of authorized shares that were not issued or reserved for any other purpose that equaled or exceeded the maximum number of underlying shares (“share reservation condition”), the Company would have been required to pay to the converting holder in respect of each $1,000 principal amount of notes being converted solely in cash in an amount equal to the sum of the daily conversion values for each of the 20 consecutive trading days during the related observation period. However, following satisfaction of the share reservation condition, the Company could settle conversions of notes through payment or delivery, as the case may be, of cash, shares of the Company’s common stock or a combination of cash and shares of its common stock, at the Company’s election. As further discussed below, the Company satisfied the share reservation condition during May 2020.

In accounting for the issuance of the Notes due 2025, on March 9, 2020, the conversion option of the Notes due 2025 was deemed an embedded derivative requiring bifurcation from the Notes due 2025 (“host contract”) and separate accounting as an embedded derivative liability, as a result of the Company not having the necessary number of authorized but unissued shares of its common stock available to settle the conversion option of the Notes due 2025 in shares. The proceeds from the Notes due 2025 were first allocated to the embedded derivative liability and the remaining proceeds were then allocated to the host contract. On March 9, 2020, the carrying amount of the embedded derivative liability of $68.7 million representing the conversion option was determined using the Binomial Lattice model and the remaining $251.3 million was allocated to the host contract. The difference between the principal amount of the Notes due 2025 and the fair value of the host contract (the “debt discount”) is amortized to interest expense using the effective interest method over the term of the Notes due 2025.

On May 20, 2020, at the Company’s annual meeting of stockholders, the stockholders approved an amendment to the Amended and Restated Certificate of Incorporation to increase the number of authorized shares of the Company’s common stock, par value $0.00001 per share, from 150,000,000 shares to 200,000,000 shares (the “Amendment”). The Amendment became effective upon filing with the Secretary of State of Delaware on May 20, 2020. As a result, the Company satisfied the share reservation condition. The Company may now settle the Notes due 2025 and warrants issued in conjunction with the Notes due 2025 through payment or delivery, as the case may be, of cash, shares of its common stock or a combination of cash and shares of its common stock, at the Company’s election. Accordingly, on May 20, 2020, the embedded derivative liability was remeasured at a fair value of $116.3 million and was then reclassified to additional paid-in-capital in the condensed consolidated balance sheet in the second quarter of 2020 and is no longer remeasured as long as it continues to meet the conditions for equity classification. The Company recorded the change in the fair value of the embedded derivative in other expense, net in the condensed consolidated statement of operations during the three and six months ended June 30, 2020.

Concurrently with the offering of the Notes due 2026 and Notes due 2028, the Company entered into separately- and privately-negotiated transactions to repurchase approximately $217.7 million aggregate principal amount of the Notes due 2025. The Company paid $217.7 million in cash and issued approximately 1.67 million shares of its common stock to the holders of the repurchased notes with an aggregate fair value of $302.7 million, representing the conversion value in excess of the principal amount of the Notes due 2025, which were fully offset by shares received from the Company’s settlement of the associated note hedging arrangements discussed below. The total amount of $217.7 million paid to partially settle the repurchases of the Notes due 2025 was allocated between the liability and equity components of the amount extinguished by determining the fair value of the liability component immediately prior to the notes repurchase and allocating that portion of the conversion price to the liability component in the amount of $184.5 million. The residual of the conversion price of $4.3 million of the repurchased Notes due 2025, net of inducement loss of $37.5 million for additional shares issued, was allocated to the equity component of the repurchased Notes due 2025 as an increase of additional paid-in capital. The fair value of the notes settlement for such repurchases was calculated using a discount rate of 4.35%, representing an estimate of the Company's borrowing rate at the date of repurchase with a remaining expected life of approximately 4.1 years. As part of the settlement of the repurchase of the Notes due 2025, the Company wrote-off the $38.5 million unamortized debt discount and $4.1 million debt issuance cost apportioned to the principal amount of Notes due 2025 repurchased. The Company recorded a loss on partial settlement of the repurchased Notes due 2025 of $9.4 million in Other income (expense), net in the six months ended June 30, 2021, representing the difference between the consideration attributed to the liability component and the sum of the net carrying amount of the liability component and unamortized debt issuance costs. Further, the Company also recorded loss on inducement of $37.5 million in Other income (expense), net in the six months ended June 30, 2021, representing the difference between the fair value of the shares that would have been issued under the original conversion terms with respect to the repurchased Notes due 2025.

During the second quarter of 2021, $0.1 million in aggregate principal amount of the Notes due 2025 were converted, and the principal amount of the converted Notes due 2025 was repaid in cash. In connection with such conversions during the second quarter of 2021, the Company also issued 485 shares of its common stock to the holders of the converted Notes due 2025, with an aggregate fair value of $0.1 million, representing the conversion value in excess of the principal amount of the Notes due 2025, which were fully offset by shares received from the settlements of the associated note hedging arrangements. Following the repurchase transactions summarized above, as of June 30, 2021, $102.2 million aggregate principal amount of the Notes due 2025 remained outstanding.

In connection with the offering of the Notes due 2025, the Company entered into privately-negotiated convertible note hedge transactions (the “Notes due 2025 Hedge”) pursuant to which the Company has the option to purchase a total of approximately 3.9 million shares of its common stock (subject to anti-dilution adjustments), which is the same number of shares initially issuable upon conversion of the notes, at a price of $81.54 per share, which is the initial conversion price of the Notes due 2025. The total cost of the convertible note hedge transactions was approximately $89.1 million. The convertible note hedge transactions are expected generally to reduce potential dilution to the Company’s common stock upon any conversion of the Notes due 2025 and/or offset any cash payments the Company is required to make in excess of the principal amount of converted notes, as the case may be.

Additionally, the Company separately entered into privately-negotiated warrant transactions in connection with the offering of the Notes due 2025 (the “2025 Warrants”) whereby the Company sold warrants to acquire approximately 3.9 million shares of the Company’s common stock (subject to anti-dilution adjustments) at an initial strike price of $106.94 per share. The Company received aggregate proceeds of approximately $71.6 million from the sale of the 2025 Warrants. If the market value per share of the Company’s common stock, as measured under the 2025 Warrants, exceeds the strike price of the 2025 Warrants, the 2025 Warrants will have a dilutive effect on the Company’s earnings per share, unless the Company elects, subject to certain conditions, to settle the 2025 Warrants in cash. Taken together, the purchase of the convertible note hedges in connection with the Notes due 2025 Hedge and the sale of the 2025 Warrants are intended to reduce potential dilution from the conversion of the Notes due 2025 and to effectively increase the overall conversion price from $81.54 to $106.94 per share. The 2025 Warrants are only exercisable on the applicable expiration dates in accordance with the agreements relating to each of the 2025 Warrants. Subject to the other terms of the 2025 Warrants, the first expiration date applicable to the 2025 Warrants is June 1, 2025, and the final expiration date applicable to the 2025 Warrants is September 23, 2025.

During the first quarter of 2021, in connection with the repurchase of $217.7 million aggregate principal amount of the Notes due 2025 summarized above, the Company entered into partial unwind agreements with respect to certain of the Notes due 2025 Hedge and the 2025 Warrants. In connection with these unwind transactions, the Company received shares of the Company’s common stock as a termination payment for the portion of the Notes due 2025 Hedge that were unwound, and the Company issued shares of its common stock as a termination payment for the portion of the 2025 Warrants that were unwound. As a result of the unwind agreements for the Notes due 2025 Hedge and the 2025 Warrants, the Company received 1.9 million of the Company’s common stock from the Notes due 2025 Hedge settlement and issued 1.8 million of the Company’s common stock from the 2025 Warrants that were unwound. Following the unwind transactions summarized above, as of June 30, 2021, options to purchase approximately 1.3 million shares of common stock remained outstanding under the Notes due 2025 Hedge, and 2025 Warrants exercisable to purchase approximately 1.3 million shares remained outstanding.

For the period from March 9, 2020, the issuance date of the Notes due 2025 Hedge and 2025 Warrants, through May 19, 2020, the number of authorized and unissued shares of the Company’s common stock that are not reserved for other purposes was less than the maximum number of underlying shares that will be required to settle the Notes due 2025 through the delivery of shares of the Company’s common stock. Accordingly, the Notes due 2025 Hedge and 2025 Warrants could only be settled on net cash settlement basis. As a result, the Notes due 2025 Hedge and 2025 Warrants were classified as a Convertible notes hedge asset and Warrants liability, respectively, in the condensed consolidated balance sheet and the change in fair value of derivatives was included in other expense, net in the condensed consolidated statement of operations.

On May 20, 2020, at the Company’s annual meeting of stockholders, the stockholders approved the Amendment and satisfied the share reservation condition (as discussed above), and as a result, the Convertible notes hedge asset and Warrants liabilities were remeasured at a fair value of $117.1 million and $96.4 million, respectively, and were then reclassified to additional paid-in-capital in the condensed consolidated balance sheet in the second quarter of 2020 and is no longer remeasured as long as they continue to meet the conditions for equity classification. The change in the fair value of the Convertible notes hedge asset and Warrants liability were recorded in other expense, net in the condensed consolidated statements of operations during the three and six months ended June 30, 2020.

On June 5, 2019, the Company issued $132.0 million aggregate principal amount of 1.0% convertible senior notes due 2024 (the “Notes due 2024”). The Notes due 2024 are general unsecured obligations and bear interest at an annual rate of 1.0% per year, payable semi-annually on June 1 and December 1 of each year, beginning December 1, 2019. The Notes due 2024 are governed by an indenture between the Company and U.S. Bank National Association, as trustee. The Notes due 2024 will mature on June 1, 2024, unless earlier repurchased by the Company or converted at the option of the holders. The Company may not redeem the notes prior to the maturity date, and no sinking fund is provided for the notes. The Notes due 2024 may be converted, under certain circumstances as described below, based on an initial conversion rate of 48.7781 shares of common stock per $1,000 principal amount (which represents an initial conversion price of $20.50 per share). The conversion rate for the Notes due 2024 will be subject to adjustment upon the occurrence of certain specified events but will not be adjusted for accrued and unpaid interest. In addition, upon the occurrence of a make-whole fundamental change (as defined in the relevant indenture), the Company will, in certain circumstances, increase the conversion rate by a number of additional shares for a holder that elects to convert its notes in connection with such make-whole fundamental change. The Company received approximately $128.0 million in net proceeds, after deducting the initial purchasers’ discount, from the issuance of the Notes due 2024.

The Notes due 2024 may be converted on any day prior to the close of business on the business day immediately preceding December 1, 2023, in multiples of $1,000 principal amount, at the option of the holder only under any of the following circumstances: (1) during any calendar quarter commencing after the calendar quarter ending on September 30, 2019 (and only during such calendar quarter), if the last reported sale price of the Company’s 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 $26.65 (130% of the conversion price) on each applicable trading day; (2) during the five business day period after any five consecutive trading day period (the “measurement period”) in which the “trading price” (as defined in the relevant indenture) per $1,000 principal amount of 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; or (3) upon the occurrence of specified corporate events. On and after December 1, 2023 until the close of business on the second scheduled trading day immediately preceding the maturity date of June 1, 2024, holders may convert their notes at any time, regardless of the foregoing circumstances. Upon the occurrence of a fundamental change (as defined in the relevant indenture), holders may require the Company to repurchase all or a portion of their Notes due 2024 for cash at a price equal to 100% of the principal amount of the notes to be repurchased plus any accrued and unpaid interest to, but excluding, the fundamental change repurchase date.

As of June 30, 2021, the sale price of the Company’s common stock was greater than or equal to $26.65 (130% of the notes conversion price) for at least 20 trading days (whether consecutive or not) during a period of 30 consecutive trading days preceding the quarter-ended June 30, 2021. As a result, as of June 30, 2021, the Notes due 2024 are convertible at the holders’ option through September 30, 2021. Accordingly, the Company classified the net carrying amount of the Notes due 2024 of $0.9 million as Debt, current on the condensed consolidated balance sheet as of June 30, 2021. From July 1, 2021 through the date Form 10-Q is available to be issued, the Company has not received any requests for conversion of the Notes due 2024.

In accounting for the issuance of the Notes due 2024, on June 5, 2019, the Company separated the Notes due 2024 into liability and equity components. The carrying amount of the liability component of approximately $95.6 million was calculated by using a discount rate of 7.75%, which was the Company’s borrowing rate on the date of the issuance of the Notes due 2024 for a similar debt instrument without the conversion feature. The carrying amount of the equity component of approximately $36.4 million, representing the conversion option, was determined by deducting the fair value of the liability component from the par value of the Notes due 2024. The equity component of the Notes due 2024 is included in additional paid-in capital in the condensed consolidated balance sheet and is not remeasured as long as it continues to meet the conditions for equity classification. The difference between the principal amount of the Notes due 2024 and the liability component (the “debt discount”) is amortized to interest expense using the effective interest method over the term of the Notes due 2024.

Debt issuance costs for the issuance of the Notes due 2024 were approximately $4.6 million, consisting of initial purchasers' discount and other issuance costs. In accounting for the transaction costs, the Company allocated the total amount incurred to the liability and equity components using the same proportions as the proceeds from the Notes due 2024. Transaction costs attributable to the liability component were approximately $3.3 million, were recorded as debt issuance cost (presented as contra debt in the condensed consolidated balance sheet) and are being amortized to interest expense over the term of the Notes due 2024. The transaction costs attributable to the equity component were approximately $1.3 million and were netted with the equity component in stockholders’ equity. As of June 30, 2021 and December 31, 2020, the unamortized deferred issuance cost for the Notes due 2024 was less than $0.1 million and $1.5 million, respectively, on the condensed consolidated balance sheets.

During the first quarter of 2021, $87.1 million in aggregate principal amount of the Notes due 2024 were converted or repurchased by the Company, and the principal amount of the converted and repurchased Notes due 2024 was repaid in cash. Of the $87.1 million in aggregate principal amount, $25.5 million in aggregate principal amount of Notes due 2024 were repurchased by the Company pursuant to separately- and privately-negotiated exchange agreements entered into in March 2021 concurrently with the issuance of Notes due 2026 and Notes due 2028. In connection with such conversions and repurchases, during the first quarter of 2021, the Company also issued 3.8 million shares of its common stock to the holders of the converted and repurchased Notes due 2024, with an aggregate fair value of $659.4 million, representing the conversion value in excess of the principal amount of the Notes due 2024. The total amount of $87.1 million paid to settle the conversions and repurchases of the Notes due 2024 during the first quarter of 2021 was allocated between the liability and equity components of the amount extinguished by determining the fair value of the liability component immediately prior to the notes settlement and allocating that portion of the conversion price to the liability component in the amount of $78.4 million. The residual of the conversion price of $8.6 million was allocated to the equity component of the Notes due 2024 as a reduction of additional paid-in capital. The fair value of the notes conversions and repurchases during the first quarter of 2021 was calculated using a discount rate of 4.25%, representing an estimate of the Company's borrowing rate at the date of repurchase with a remaining expected life of approximately 3.3 years. As part of the settlement of the conversions and repurchases, the Company wrote-off the $16.7 million unamortized debt discount and $1.4 million debt issuance cost apportioned to the principal amount of Notes due 2024 were converted and repurchased. The Company also recorded a loss on partial settlement of the converted and repurchased Notes due 2024 of $9.5 million in Other income (expense), net in the six months ended June 30, 2021, representing the difference between the consideration attributed to the liability component and the sum of the net carrying amount of the liability component and unamortized debt issuance costs. Following the conversions and repurchases summarized above, as of June 30, 2021, $1.1 million aggregate principal amount of the Notes due 2024 remained outstanding.

In connection with the offering of the Notes due 2024, the Company entered into privately-negotiated convertible note hedge transactions (the “Notes due 2024 Hedge”) pursuant to which the Company has the option to purchase a total of approximately 6.4 million shares of its common stock (subject to anti-dilution adjustments), which is the same number of shares initially issuable upon conversion of the notes, at a price of $20.50 per share, which is the initial conversion price of the Notes due 2024. The total cost of the convertible note hedge transactions was approximately $36.3 million. The Notes due 2024 Hedge transactions are expected generally to reduce potential dilution to the Company’s common stock upon any conversion of the Notes due 2024 and/or offset any cash payments the Company is required to make in excess of the principal amount of converted notes, as the case may be.

Additionally, the Company separately entered into privately-negotiated warrant transactions in connection with the offering of the Notes due 2024 (the “2024 Warrants”) whereby the Company sold warrants to acquire approximately 6.4 million shares of the Company’s common stock (subject to anti-dilution adjustments) at an initial strike price of $25.23 per share. The Company received aggregate proceeds of approximately $29.8 million from the sale of the 2024 Warrants. If the market value per share of the Company’s common stock, as measured under the 2024 Warrants, exceeds the strike price of the 2024 Warrants, the 2024 Warrants will have a dilutive effect on the Company’s earnings per share, unless the Company elects, subject to certain conditions, to settle the 2024 Warrants in cash. Taken together, the purchase of the Notes due 2024 Hedge transactions and the sale of the 2024 Warrants are intended to reduce potential dilution from the conversion of the Notes due 2024 and to effectively increase the overall conversion price from $20.50 to $25.23 per share. The 2024 Warrants are only exercisable on the applicable expiration dates in accordance with the 2024 Warrants. Subject to the other terms of the Warrants, the first expiration date applicable to the 2024 Warrants is September 1, 2024, and the final expiration date applicable to the 2024 Warrants is April 22, 2025.

During the first quarter of 2021, in connection with the repurchase of $25.5 million aggregate principal amount of the Notes due 2024 summarized above, the Company entered into partial unwind agreements with respect to certain of the Notes due 2024 Hedge and received 1.1 million shares of its common stock as a termination payment for the portion of the Notes due 2024 Hedge that were unwound. In addition to the unwind transactions discussed above, the Company also received 2.7 million shares of the Company’s common stock from the Notes due 2024 Hedge settlements as a result of the conversion of $61.5 million in aggregate principal amount of the Notes due 2024 in the first quarter of 2021. In addition, the Company entered into partial unwind agreements with respect to certain of the 2024 Warrants in connection with the repurchase and conversion of $87.1 million in aggregate principal amount of the Notes due 2024 during the first quarter of 2021 and issued 3.8 million shares of its common stock as a termination payment for the portion of the 2024 Warrants that were unwound. Following the transactions summarized above, as of June 30, 2021, options to purchase a total of approximately 0.1 million shares remained outstanding under the Notes due 2024 Hedge and 2024 Warrants exercisable to purchase a total of approximately 0.1 million shares remained outstanding under the 2024 Warrants.

In August 2018, the Company sold $65.0 million aggregate principal amount of 4.0% convertible senior notes due 2023 (the “Notes due 2023”) in a private placement. On May 30, 2019, the Company entered into separately and privately-negotiated transactions with certain holders of the Notes due 2023 resulting in the repurchase and exchange, as of June 5, 2019, of $60.0 million aggregate principal amount of the notes in consideration for the issuance of 10,801,080 shares of common stock and separate cash payments totaling $6.0 million. As of both June 30, 2021 and December 31, 2020, $5.0 million aggregate principal amount of the Notes due 2023 remained outstanding.

The remaining outstanding Notes due 2023 are general unsecured obligations and bear interest at a rate of 4.0% per year, payable semi-annually on February 1 and August 1 of each year. The Notes due 2023 are governed by an indenture between the Company and U.S. Bank National Association, as trustee. The remaining outstanding Notes due 2023 will mature on August 1, 2023, unless earlier repurchased by the Company or converted at the option of the holders. The Company may not redeem the remaining Notes due 2023 prior to the maturity date, and no sinking fund is provided for such notes. The remaining Notes due 2023 are convertible, at a holder’s election, in multiples of $1,000 principal amount, into shares of the Company’s common stock based on the applicable conversion rate. The initial conversion rate for such notes is 180.018 shares of common stock per $1,000 principal amount of notes (which is equivalent to an initial conversion price of approximately $5.56 per share). The conversion rate and the corresponding conversion price are subject to adjustment upon the occurrence of certain events but will not be adjusted for any accrued and unpaid interest. Holders of the remaining Notes due 2023 who convert their notes in connection with a make-whole fundamental change (as defined in the applicable indenture) are, under certain circumstances, entitled to an increase in the conversion rate. Additionally, in the event of a fundamental change, holders of the remaining Notes due 2023 may require the Company to repurchase all or a portion of their notes at a price equal to 100% of the principal amount of notes, plus any accrued and unpaid interest, including any additional interest to, but excluding, the repurchase date. Holders may convert all or any portion of their Notes due 2023 at their option at any time prior to the close of business on the business day immediately preceding the maturity date, in multiples of $1,000 principal amount.

The Company entered into an agreement with a third party in the fourth quarter of 2017 to sell certain current and future receivables at a discount. In December 2017, the third party made an initial purchase of receivables that resulted in net proceeds to the Company of $2.8 million. This transaction was recorded as debt on the accompanying consolidated balance sheets, and the debt balance was relieved in January 2019 as the underlying receivables were settled. During the year ended December 31, 2018, the third party made three additional purchases of receivables that resulted in total net proceeds to the Company of $5.6 million. These transactions were recorded as debt on the accompanying condensed consolidated balance sheets, and the total associated debt balance will be relieved by September 2021 as the underlying receivables are settled. As of June 30, 2021, the total sale of long-term financing receivable recorded as debt of $0.6 million remained outstanding.