Convertible Senior Notes and Capped Call Transactions

12 Months Ended

Dec. 31, 2021

Debt Disclosure [Abstract]

Convertible Senior Notes and Capped Call Transactions

Convertible Senior Notes and Capped Call Transactions

Convertible Senior Notes due 2024 and Capped Calls

In March 2019, the Company issued $230.0 million aggregate principal amount of its 0.750% Convertible Senior Notes due 2024 in a private placement, which amount includes $30.0 million aggregate principal amount of such Notes issued pursuant to the exercise in full by the initial purchasers of their option to purchase additional 2024 Notes. Interest on the Notes is payable semi-annually in arrears on March 1 and September 1 of each year, beginning on September 1, 2019.

The 2024 Notes will mature on March 1, 2024, unless earlier repurchased or redeemed by the Company or converted pursuant to their terms. The total net proceeds from the offering of the 2024 Notes, after deducting debt issuance costs, paid, or payable by the Company, was approximately $221.4 million.

Each $1,000 in principal amount of the 2024 Notes is initially convertible into 25.9182 shares of the Company’s common stock par value $0.001, which is equivalent to an initial conversion price of approximately $38.58 per share. The conversion rate is subject to adjustment upon the occurrence of certain specified events but will not be adjusted for any accrued and unpaid interest. In addition, following certain corporate events that occur prior to the maturity date, the Company will increase the conversion rate for a holder who elects to convert its 2024 Notes in connection with such a corporate event. The 2024 Notes are not redeemable prior to the maturity date of the 2024 Notes and no sinking fund is provided for the 2024 Notes. If the Company undergoes a fundamental change (as defined in the indenture governing the 2024 Notes) prior to the maturity date, holders may require the Company to repurchase for cash all or any portion of their Notes in principal amounts of $1,000 or a multiple thereof at a fundamental change repurchase price equal to 100% of the principal amount of the 2024 Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date.

Holders of the 2024 Notes may convert their 2024 Notes at their option at any time prior to the close of business on the business day immediately preceding November 1, 2023, in multiples of $1,000 principal amount, only under the following circumstances: (1) during any calendar quarter commencing after the calendar quarter ending on June 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 130% of the conversion price for the 2024 Notes on each applicable trading day as determined by the Company; (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 indenture governing the 2024 Notes) per $1,000 principal amount of 2024 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 2024 Notes on each such trading day; or (3) upon the occurrence of specified corporate events. On or after November 1, 2023, holders may convert all or any portion of their 2024 Notes at any time prior to the close of business on the second scheduled trading day immediately preceding the maturity date, regardless of the foregoing circumstances. Upon conversion, the Company will pay or deliver, as the case may be, cash, shares of its common stock, or a combination of cash and shares of its common stock, at the Company’s election.

During the three months ended December 31, 2021, the conditions allowing holders of the 2024 Notes to convert were not met.

The 2024 Notes are senior unsecured obligations and will rank senior in right of payment to any of the Company’s indebtedness that is expressly subordinated in right of payment to the 2024 Notes; equal in right of payment with the Company’s existing and future liabilities that are not so subordinated; effectively subordinated to any of the Company’s secured indebtedness to the extent of the value of the assets securing such indebtedness; and structurally junior to all indebtedness and other liabilities (including trade payables) of current or future subsidiaries of the Company.

In accounting for the issuance of the 2024 Notes, the Company separated the 2024 Notes into liability and equity components. The carrying amount of the liability component was calculated by measuring the fair value of a similar debt instrument that does not have an associated convertible feature. The carrying amount of the equity component representing the conversion option was $52.9 million and was determined by deducting the fair value of the liability component from the par value of the 2024 Notes. The equity component is not remeasured as long as it continues to meet the conditions for equity classification. The excess of the principal amount of the liability component over its carrying amount, or the debt discount, is amortized to interest expense at an effective interest rate over the contractual term of the 2024 Notes.

In accounting for the transaction costs related to the 2024 Notes, the Company allocated the total amount incurred of approximately $8.6 million to the liability and equity components of the 2024 Notes based on the proportion of the proceeds allocated to the debt and equity components. Issuance costs attributable to the liability component were approximately $6.6 million, were recorded as an additional debt discount and are amortized to interest expense using the effective interest method over the contractual term of the 2024 Notes. Issuance costs attributable to the equity component were approximately $2.0 million and recorded as a reduction of additional paid in capital in stockholders’ equity.

In connection with the offering of the 2024 Notes, the Company entered into privately-negotiated capped call option transactions with certain counterparties (the “2024 capped call”). The 2024 capped calls each have an initial strike price of approximately $38.58 per share, subject to certain adjustments, which corresponds to the initial conversion price of the 2024 Notes. The 2024 capped calls have initial cap prices of $57.16 per share, subject to certain adjustment events. The 2024 capped calls cover, subject to anti-dilution adjustments, approximately 5.96 million shares of common stock. The 2024 capped calls are generally intended to reduce or offset the potential dilution to the common stock upon any conversion of the 2024 Notes with such reduction or offset, as the case may be, subject to a cap based on the cap price. The 2024 capped calls expire on March 1, 2024, subject to earlier exercise. The 2024 capped calls are subject to either adjustment or termination upon the occurrence of specified extraordinary events affecting the Company, including a merger event, a tender offer, and a nationalization, insolvency or delisting involving the Company. In addition, the 2024 capped calls are subject to certain specified additional disruption events that may give rise to a termination of the 2024 capped calls, including changes in law, failure to deliver, and hedging disruptions. The 2024 capped calls are recorded in stockholders’ equity and are not accounted for as derivatives. The net cost of $23.2 million incurred to purchase the 2024 capped calls was recorded as a reduction to additional paid-in capital in the accompanying consolidated balance sheet.

The remaining term over which the 2024 Notes’ debt discount and debt issuance costs will be amortized is 2.2 years. The effective interest rate on the debt was 3.43% for the period ended December 31, 2021.

Convertible Senior Notes due 2026 and Capped Calls

In December 2020, the Company issued $517.5 million aggregate principal amount of its 0% Convertible Senior Notes due 2026 in a private placement, which amount includes $67.5 million aggregate principal amount of such Notes issued pursuant to the exercise in full by the initial purchasers of their option to purchase additional 2026 Notes.

The 2026 Notes will mature on December 15, 2026, unless earlier repurchased or redeemed by the Company or converted pursuant to their terms. The total net proceeds from the offering of the 2026 Notes, after deducting debt issuance costs, paid or payable by the Company, was approximately $505.3 million.

Each $1,000 in principal amount of the 2026 Notes is initially convertible into 13.2933 shares of the Company’s common stock par value $0.001, which is equivalent to an initial conversion price of approximately $75.23 per share. The conversion rate is subject to adjustment upon the occurrence of certain specified events but will not be adjusted for any accrued and unpaid special interest. In addition, following certain corporate events that occur prior to the maturity date, the Company will increase the conversion rate for a holder who elects to convert its 2026 Notes in connection with such a corporate event. The 2026 Notes are not redeemable prior to the maturity date of the 2026 Notes and no sinking fund is provided for the 2026 Notes. If the Company undergoes a fundamental change (as defined in the indenture governing the 2026 Notes) prior to the maturity date, holders may require the Company to repurchase for cash all or any portion of their Notes in principal amounts of $1,000 or a multiple thereof at a fundamental change repurchase price equal to 100% of the principal amount of the 2026 Notes to be repurchased, plus accrued and unpaid special interest to, but excluding, the fundamental change repurchase date.

Holders of the 2026 Notes may convert their 2026 Notes at their option at any time prior to the close of business on the business day immediately preceding August 15, 2026, in multiples of $1,000 principal amount, only under the following circumstances: (1) during any calendar quarter commencing after the calendar quarter ending on March 31, 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 2026 Notes on each applicable trading day as determined by the Company; (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 indenture governing the 2026 Notes) per $1,000 principal amount of 2026 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 2026 Notes on each such trading day; (3) with respect to any Notes that the Company calls 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 August 15, 2026, holders may convert all or any portion of their 2026 Notes at any time prior to the close of business on the second scheduled trading day immediately preceding the maturity date, regardless of the foregoing circumstances. Upon conversion, the Company will pay or deliver, as the case may be, cash, shares of its common stock or a combination of cash and shares of its common stock, at the Company’s election.

During the three months ended December 31, 2021, the conditions allowing holders of the 2026 Notes to convert were not met.

The 2026 Notes are senior unsecured obligations and will rank senior in right of payment to any of the Company’s indebtedness that is expressly subordinated in right of payment to the 2026 Notes; equal in right of payment with the Company’s existing and future liabilities that are not so subordinated; effectively subordinated to any of the Company’s secured indebtedness to the extent of the value of the assets securing such indebtedness; and structurally junior to all indebtedness and other liabilities (including trade payables) of current or future subsidiaries of the Company.

In accounting for the issuance of the 2026 Notes, the Company separated the 2026 Notes into liability and equity components. The carrying amount of the liability component was calculated by measuring the fair value of a similar debt instrument that does not have an associated convertible feature. The carrying amount of the equity component representing the conversion option was $162.5 million and was determined by deducting the fair value of the liability component from the par value of the 2026 Notes. The equity component is not remeasured as long as it continues to meet the conditions for equity classification. The excess of the principal amount of the liability component over its carrying amount, or the debt discount, is amortized to interest expense at an effective interest rate over the contractual term of the 2026 Notes.

In accounting for the transaction costs related to the 2026 Notes, the Company allocated the total amount incurred of approximately $12.2 million to the liability and equity components of the 2026 Notes based on the proportion of the proceeds allocated to the debt and equity components. Issuance costs attributable to the liability component were approximately $8.5 million, were recorded as an additional debt discount and are amortized to interest expense using the effective interest method over the contractual terms of the 2026 Notes. Issuance costs attributable to the equity component were approximately $3.7 million and recorded as a reduction of additional paid in capital in stockholders’ equity.

The remaining term over which the 2026 Notes’ debt discount and debt issuance costs will be amortized is 4.9 years. The effective interest rate on the debt was 5.49% for the period ended December 31, 2021.

In connection with the offering of the 2026 Notes, the Company entered into privately-negotiated capped call option transactions with certain counterparties (the “2026 capped call”). The 2026 capped calls each have an initial strike price of approximately $75.23 per share, subject to certain adjustments, which corresponds to the initial conversion price of the 2026 Notes. The 2026 capped calls have initial cap prices of $105.58 per share, subject to certain adjustment events. The 2026 capped calls cover, subject to anti-dilution adjustments, approximately 6.88 million shares of common stock. The 2026 capped calls are generally intended to reduce or offset the potential dilution to the common stock upon any conversion of the 2026 Notes with such reduction or offset, as the case may be, subject to a cap based on the cap price. The 2026 capped calls expire on December 15, 2026, subject to earlier exercise. The 2026 capped calls are subject to either adjustment or termination upon the occurrence of specified extraordinary events affecting the Company, including a merger event, a tender offer, and a nationalization, insolvency or delisting involving the Company. In addition, the 2026 capped calls are subject to certain specified additional disruption events that may give rise to a termination of the 2026 capped calls, including changes in law, failure to deliver, and hedging disruptions. The 2026 capped calls are recorded in stockholders’ equity and are not accounted for as derivatives. The net cost of $46.1 million incurred to purchase the 2026 capped calls was recorded as a reduction to additional paid-in capital in the accompanying consolidated balance sheet.

The net carrying amount of the liability component of the Notes was as follows:

	December 31,
	2021		2020
	(In thousands)
Principal	$	747,500	$	747,500
Unamortized discount	(162,960)		(196,269)
Unamortized issuance costs	(10,302)		(12,799)
Net carrying amount	$	574,238	$	538,432

The net carrying amount of the equity component of the Notes was as follows:

	December 31,
	2021		2020
	(In thousands)
Proceeds allocated to the conversion options (debt discount)	$	215,434	$	215,434
Issuance costs	(5,783)		(5,783)
Net carrying amount	$	209,651	$	209,651

The following table sets forth the interest expense recognized related to the Notes:

	Year Ended December 31,
	2021		2020		2019
	(In thousands)
Contractual interest expense	$	1,725	$	1,725	$	1,438
Amortization of issuance costs	2,499		1,340		956
Amortization of debt discount	33,309		11,564		7,605
Total interest expense	$	37,533	$	14,629	$	9,999

Interest expense of $37.5 million, $14.6 million, and $10.0 million is reflected as a component of interest expense, net in the accompanying consolidated statement of operations for the years ended December 31, 2021, 2020, and 2019, respectively.