
(In thousands)	Coupon Interest Rate	Effective Interest Rate	Fair Value of Liability Component at Issuance (1)		March 31, 2020		December 31, 2019
2028 Convertible notes	0.375%	5.2%	$	790,608	$	1,150,000	$	—
2027 Convertible notes	0.375%	6.3%	472,501		747,500		747,500
2025 Convertible notes	1.000%	6.0%	227,103		315,049		415,049
Total Convertible notes					2,212,549		1,162,549
Less: Debt discount (2)					(667,228)		(342,463)
Less: Debt issuance costs (3)					(31,015)		(16,481)
Net convertible debt					$	1,514,306	$	803,605

(1)As each of the convertible instruments may be settled in cash upon conversion, for accounting purposes, they were separated into a liability component and an equity component. The amount allocated to the equity component is the difference between the principal value of the instrument and the fair value of the liability component at issuance. The resulting debt discount is being amortized to interest expense at the respective effective interest rate over the contractual term of the debt. A portion of the 2025 Convertible Notes have been extinguished or converted. The fair value of the liability component at issuance reflected above represents the liability value at issuance for the applicable portion of the 2025 Notes which remain outstanding at March 31, 2020 and December 31, 2019. The fair value of the liability component of the 2025 Notes at issuance was $654.8 million with the equity component being $269.7 million.

In January 2018, the Company issued and sold $690.0 million in aggregate principal amount of 1.0% Convertible Notes (the “January 2025 Notes”) with a maturity date of January 15, 2025. The January 2025 Notes accrue interest at a fixed rate of 1.0% per year, payable semi-annually in arrears on January 15 and July 15 of each year, beginning on July 15, 2018. The net proceeds from the issuance of the January 2025 Notes were approximately $671.1 million, after deducting underwriting discounts and commissions and the offering expenses payable by the Company.

In June 2018, the Company issued and sold an additional $218.5 million in aggregate principal amount of 1.0% Convertible Notes (the “June 2025 Notes”). The June 2025 Notes were issued under the same indenture pursuant to which the Company previously issued the January 2025 Notes (the “Indenture”). The January 2025 Notes and the June 2025 Notes (collectively, the “2025 Notes”) have identical terms and will be treated as a single series of securities. The net proceeds from the issuance of the June 2025 Notes were approximately $225.3 million, after deducting underwriting discounts and commissions and the offering expenses payable by the Company.

In March 2019, the Company issued and sold $747.5 million in aggregate principal amount of 0.375% Convertible Notes (the “2027 Notes”) with a maturity date of March 15, 2027. The 2027 Notes accrue interest at a fixed rate of 0.375% per year, payable semi-annually in arrears on March 15 and September 15 of each year, beginning on September 15, 2019. The net proceeds from the issuance of the 2027 Notes were approximately $729.5 million, after deducting underwriting discounts and commissions and the offering expenses payable by the Company.

The Company utilized a portion of the proceeds from the issuance of the 2027 Notes to settle a portion of the 2025 Notes in privately negotiated transactions. In March 2019, the Company used cash of $494.1 million and an aggregate of 2.2 million shares of the Company’s common stock valued at $182.4 million for total consideration of $676.5 million to settle $493.4 million of the 2025 Notes, of which $375.0 million was allocated to the liability component, $300.8 million was allocated to the equity component, and $0.7 million was used to pay off interest accrued on the 2025 Notes. The consideration transferred was allocated to the liability and equity components of the 2025 Notes using the equivalent rate that reflected the borrowing rate for a similar non-convertible debt instrument immediately prior to settlement. The transaction resulted in a loss on settlement of convertible notes of $10.6 million, which is recorded in interest expense in the Company’s condensed consolidated statement of operations. The loss represents the difference between (i) the fair value of the liability component and (ii) the sum of the carrying value of the debt component and any unamortized debt issuance costs at the time of repurchase.

In February 2020, the Company issued and sold $1,150.0 million in aggregate principal amount of 0.375% Convertible Notes (the “2028 Notes” and, collectively with the 2025 Notes and the 2027 Notes, the “Notes”) with a maturity date of March 1, 2028. The 2028 Notes accrue interest at a fixed rate of 0.375% per year, payable semi-annually in arrears on March 1 and September 1 of each year, beginning on September 1, 2020. The net proceeds from the issuance of the 2028 Notes were approximately $1,125.6 million, after deducting underwriting discounts and commissions and the offering expenses payable by the Company.

In February 2020, the Company used $150.1 million of the proceeds from the issuance of the 2028 Notes to settle $100.0 million of the 2025 Notes, of which $85.5 million was allocated to the liability component, $64.2 million, net of a tax impact of $0.3 million, was allocated to the equity component, and $0.1 million was used to pay off interest accrued on the 2025 Notes. The consideration transferred was allocated to the liability and equity components of the 2025 Notes using the equivalent rate that reflected the borrowing rate for a similar non-convertible debt instrument immediately prior to settlement. The transaction resulted in a loss on settlement of convertible notes of $8.0 million, which is recorded in interest expense in the Company’s condensed consolidated statement of operations. The loss represents the difference between (i) the fair value of the liability component and (ii) the sum of the carrying value of the debt component and any unamortized debt issuance costs at the time of repurchase.

Until the six-months immediately preceding the maturity date of the applicable series of Notes, each series of Notes is convertible only upon the occurrence of certain events and during certain periods, as set forth in the Indentures. The Notes will be convertible into cash, shares of the Company’s common stock (plus, if applicable, cash in lieu of any fractional share), or a combination of cash and shares of the Company’s common stock, at the Company’s election. On or after the date that is six-months immediately preceding the maturity date of the applicable series of Notes until the close of business on the second scheduled trading day immediately preceding the maturity date, holders may convert such Notes at any time.

It is the Company’s intent and policy to settle all conversions through combination settlement. The initial conversion rate is 13.26, 8.96, and 8.21 shares of common stock per $1,000 principal amount for the 2025 Notes, 2027 Notes, and 2028 Notes, respectively, which is equivalent to an initial conversion price of approximately $75.43, $111.66, and $121.84 per share of the Company’s common stock for the 2025 Notes, 2027 Notes, and 2028 Notes, respectively. The conversion rate is subject to adjustment upon the occurrence of certain specified events but will not be adjusted for accrued and unpaid interest. In addition, holders of the Notes who convert their Notes in connection with a “make-whole fundamental change” (as defined in the Indenture), will, under certain circumstances, be entitled to an increase in the conversion rate.

If the Company undergoes a “fundamental change” (as defined in the Indenture), holders of the Notes may require the Company to repurchase for cash all or part of their Notes at a repurchase price equal to 100% of the principal amount of the Notes to be repurchased, plus accrued and unpaid interest.

The Notes are the Company’s senior unsecured obligations and (i) rank senior in right of payment to all of its future indebtedness that is expressly subordinated in right of payment to the Notes; equal in right of payment to all of the Company’s future liabilities that are not so subordinated, unsecured indebtedness; (ii) are effectively junior to all of our existing and future secured indebtedness and other secured obligations, to the extent of the value of the assets securing that indebtedness and other secured obligations; and (iii) are structurally subordinated to all indebtedness and other liabilities of the Company’s subsidiaries.

While the Notes are currently classified on the Company’s condensed consolidated balance sheets at March 31, 2020 as long-term, the future convertibility and resulting balance sheet classification of this liability will be monitored at each quarterly reporting date and will be analyzed dependent upon market prices of the Company’s common stock during the prescribed measurement periods. In the event that the holders of the Notes have the election to convert the Notes at any time during the prescribed measurement period, the Notes would then be considered a current obligation and classified as such.

The Company allocates total transaction costs of the Notes to the liability and equity components based on their relative values. Transaction costs attributable to the liability component are amortized to interest expense over the term of the Notes, and transaction costs attributable to the equity component are netted with the equity component in stockholders’ equity. The following table summarizes the original transaction costs at the time of issuance for each set of Notes and the respective allocation to the liability and equity components:


(In thousands)	January 2025 Notes		June 2025 Notes		2027 Notes		2028 Notes
Transaction costs allocated to:
Liability component	$	13,569	$	5,052	$	11,395	$	16,811
Equity component	5,340		2,311		6,632		7,642
Total transaction costs	$	18,909	$	7,363	$	18,027	$	24,453


	Three Months Ended March 31,
(In thousands)	2020		2019
Debt issuance costs amortization	$	822	$	685
Debt discount amortization	13,731		8,394
Loss on settlement of convertible notes	7,954		10,558
Coupon interest expense	1,932		2,108
Total interest expense on convertible notes	24,439		21,745
Other interest expense	714		245
Total interest expense	$	25,153	$	21,990