The carrying value of the Company’s convertible senior notes is as follows:



	December 31, 2023			December 31, 2022
	(Amounts in thousands)
0.375% Convertible Senior Notes due 2024:
Principal amount	$	69,700		$	287,470
Unamortized debt issuance costs		(248	)		(2,855	)
Carrying amount - Convertible Senior Notes due 2024, net	$	69,452		$	284,615
1.00% Convertible Senior Notes due 2028:
Principal amount	$	600,000		$	—
Unamortized debt discount		(81,457	)		—
Unamortized debt issuance costs		(8,400	)		—
Carrying amount - Convertible Senior Notes due 2028, net	$	510,143		$	—

On December 14, 2023, the Company issued $600.0 million aggregate principal amount of its 2023 Notes in the Exchange and Subscription Agreements with a limited number of holders of its outstanding 2019 Notes and certain other qualified institutional buyers pursuant to Rule 144A under the Securities Act. Pursuant to the Exchange and Subscription Agreements, the Company exchanged $217.7 million of its 2019 Notes, which were cancelled upon exchange, for $309.9 million aggregate principal amount of the 2023 Notes (the “Exchange Transaction”) and issued $290.1 million aggregate principal amount of the 2023 Notes in a private placement to accredited institutional buyers (the “Subscription Transactions”) for $290.1 million in cash.

The Company evaluated the Exchange Transaction and determined approximately $29.6 million of the $217.7 million principal of the exchanged 2019 Notes should be accounted for as extinguishments of debt and approximately $188.1 million should be accounted for as modification of debt. As a result, we recognized a $12.7 million loss on extinguishment of debt in our consolidated statements of comprehensive income for the year ended December 31, 2023, inclusive of $0.1 million of unamortized debt issuance costs. Under modification accounting, the carrying amount of the modified 2019 Notes was reduced by $2.8 million, with a corresponding increase to additional paid-in capital, to account for the increase in the fair value of the embedded conversion option, representing a debt discount of the modified 2019 Notes. The aggregate debt discount of $82.1 million, comprised of $79.3 million increase in principal of the modified 2019 Notes and a $2.8 million increase in the fair value of the embedded conversion option, is as a direct reduction from the carrying value of the convertible debt on our consolidated balance sheets. This amount will be accreted into interest expense in the consolidated statements of comprehensive income using the effective interest method over the term of the 2023 Notes.

Proceeds from the Subscription Transactions were $276.1 million, net of debt issuance costs of $14.0 million. The Exchange Transaction resulted in $6.2 million of the debt issuance costs related to the modified 2019 Notes, which were expensed as incurred in accordance with modification accounting, and $7.8 million of deferred debt issuance costs related to the 2023 Notes, which were recorded as a direct deduction to the carrying value of the 2023 Notes on the Company’s consolidated balance sheets. The Company will amortize the $7.8 million of debt issuance costs of the 2023 Notes into amortization of debt issuance costs in the Company’s consolidated statements of comprehensive income over the remaining term of the 2023 Notes. The carrying value of the 2023 Notes of $510.1 million is included in long-term debt on the Company's consolidated balance sheets as of December 31, 2023.

The Company used $14.4 million of the proceeds from the Subscription Transactions to repurchase shares of its common stock from certain purchasers of the 2023 Notes. See Note 12, “Stockholders’ Equity - Share Repurchases” for additional information related to this repurchase. The Company will also use a portion of the proceeds to finance in part, the settlement upon conversion or repurchase of the remaining 2019 Notes at or prior to maturity. The remainder of the proceeds will be used for working capital

and general corporate purposes, including to fund possible acquisitions of, or investments in, complementary businesses, products, services and technologies.

The 2023 Notes are senior, unsecured obligations of the Company, and bear interest at a rate of 1.00% per year. Interest is payable semi-annually in arrears on each June 15 and December 15, commencing on June 15, 2024. The 2023 Notes will mature on December 15, 2028, unless earlier redeemed, repurchased or converted. The initial conversion rate for the 2023 Notes is 4.9247 shares of the Company's common stock per $1,000 principal amount of 2023 Notes, which is equivalent to an initial conversion price of $203.06 per share and represents a 30% premium over the last reported sale price of $156.20 per share on December 6, 2023, the date on which the 2023 Notes were priced. Prior to the close of business on the business day immediately preceding September 15, 2028, the 2023 Notes will be convertible at the options of the holders of 2023 Notes only upon the satisfaction of specified conditions and during certain periods into cash up to their principal amount, and into cash, shares of the Company's common stock or a combination thereof, at the Company's election, for the conversion value above the principal amount, if any. Thereafter until the close of business on the second scheduled trading day immediately preceding the maturity date, the 2023 Notes will be convertible at the option of the holders of 2023 Notes at any time regardless of these conditions. The Company may redeem for cash, all or a portion of the 2023 Notes, at its option, on or after December 18, 2026 and prior to the 21st scheduled trading day immediately preceding the maturity date at a redemption price of 100% of the principal amount of the 2023 Notes to be redeemed, plus accrued and unpaid interest to, but excluding the redemption date, if certain conditions are met in accordance to the indenture governing the 2023 Notes (the “2023 Notes Indenture”).

If the Company undergoes a “fundamental change” (as defined in the 2023 Notes Indenture), the holders of the 2023 Notes may require the Company to repurchase for cash all or part of their 2023 Notes at a purchase price equal to 100% of the principal amount of the 2023 Notes to be repurchased, plus accrued and unpaid interest, if any, up to, but excluding, the fundamental change repurchase date. In addition, if certain “make-whole fundamental changes” (as defined in 2023 Notes Indenture) occur or the Company calls all or a portion of the 2023 Notes for redemption, the Company will, in certain circumstances, increase the conversion rate for any 2023 Notes converted in connection with such make-whole fundamental change or any 2023 Notes called for redemption that are converted during the related redemption period.

Interest expense recognized on the 2023 Notes in 2023 was $0.2 million and $0.6 million for the contractual coupon interest and accretion of the debt discount, respectively. Amortization of debt issuance costs recorded in 2023 related to the 2023 Notes was $6.3 million, which includes the $6.2 million of debt issuance costs recorded under modification accounting mentioned above and $0.1 million amortization of debt issuance costs related to the capitalized portion of the costs. The effective interest rate on the 2023 Notes is 4.39%, which included the interest on the 2023 Notes and amortization of the debt discount and issuance costs. As of December 31, 2023, the carrying value of the 2023 Notes was $510.1 million and the fair value of the principal was $596.0 million. The fair value of the 2023 Notes was determined based on the most recent trade activity of the 2023 Notes as of December 31, 2023.

The 2023 Notes Indenture contains customary terms and events of default. If an event of default (other than certain events of bankruptcy, insolvency or reorganization involving the Company) occurs and is continuing, the holders of at least 25% in aggregate principal amount of the outstanding 2023 Notes may declare 100% of the principal of, and any accrued and unpaid interest on, all of the 2023 Notes to be due and payable. Upon the occurrence of certain events of bankruptcy, insolvency or reorganization involving the Company, 100% of the principal of and accrued and unpaid interest, if any, on all of the 2023 Notes will become due and payable automatically. Notwithstanding the foregoing, the 2023 Notes provide that, to the extent the Company elects and for up to 365 days, the sole remedy for an event of default relating to certain failures by the Company to comply with certain reporting covenants consist exclusively of the right to receive additional interest on the 2023 Notes. The Company is not aware of any events of default that would allow holders to declare the principal of, and any accrued and unpaid interest on, all of the 2023 Notes to be due and payable.

The Company issued $287.5 million aggregate principal amount of the 2019 Notes on July 19, 2019 in a transaction which included the underwriters’ exercise in full of an option to purchase an additional $37.5 million aggregate principal amount of 2019 Notes (the “Notes Offering”). The net proceeds of the Notes Offering, after deducting underwriting discounts and

commissions and other related offering expenses payable by the Company, were approximately $278.5 million. Immediately following the closing of the Exchange Transaction mentioned above, $69.7 million in aggregate principal amount of the 2019 Notes remain outstanding.

The 2019 Notes are senior, unsecured obligations of the Company, and bear interest at a rate of 0.375% per year. Interest is payable semi-annually in arrears on January 15 and July 15 of each year, beginning on January 15, 2020. The remaining 2019 Notes will mature on July 15, 2024, unless earlier repurchased or converted in accordance with their terms. The initial conversion rate for the 2019 Notes is 8.6749 shares of the Company’s common stock per $1,000 principal amount of 2019 Notes (which is equivalent to an initial conversion price of approximately $115.28 per share). Prior to the close of business on the business day immediately preceding April 15, 2024, the 2019 Notes will be convertible at the option of the holders of 2019 Notes only upon the satisfaction of specified conditions and during certain periods. Thereafter until the close of business on the second scheduled trading day immediately preceding the maturity date, the remaining 2019 Notes will be convertible at the options of the holders of 2019 Notes at any time regardless of these conditions. Prior to March 4, 2022, conversion of the 2019 Notes could have been settled in cash, shares of the Company’s common stock or a combination thereof, at the Company’s election. On March 4, 2022, the Company entered into the Second Supplemental Indenture for the 2019 Notes, which irrevocably elected to settle the conversion of the 2019 Notes using a combination of cash and the Company’s common stock, settling the par value of the 2019 Notes in cash and any excess conversion premium in shares. The 2019 Notes are not redeemable by the Company prior to maturity.

Holders of 2019 Notes may require the Company to repurchase their 2019 Notes upon the occurrence of a fundamental change prior to maturity at a repurchase price equal to 100% of the principal amount thereof, plus accrued and unpaid interest to, but excluding, the date of repurchase. In connection with certain corporate events, the Company will, under certain circumstances, increase the conversion rate for holders of 2019 Notes who elect to convert their 2019 Notes in connection with such corporate events.

During the fourth quarter of 2023, the closing price of the Company’s common stock exceeded 130% of the conversion price of the 2019 Notes for more than 20 trading days of the last 30 consecutive trading days of the quarter. As a result, the 2019 Notes are convertible at the option of the holders of the 2019 Notes during the first quarter of 2024, the quarter immediately following the quarter when conditions are met, as stated in the terms of the 2019 Notes. These conditions have been met each quarter since the third quarter of 2020. As a result, as of the date of this filing and prior to the Exchange Transaction mentioned above, the Company received requests to convert $0.2 million aggregate principal amount of the 2019 Notes and all but $0.1 million of the requests have been settled as of December 31, 2023. The remaining outstanding requests for conversions will settle in the first quarter of 2024. The conversions resulted in the issuance of a nominal number of shares of the Company’s common stock to the note holders. Because the 2019 Notes mature within one year of the report date, the Company classifies the carrying value of the 2019 Notes of $69.5 million as current liabilities on the Company's consolidated balance sheets at December 31, 2023.

Prior to the adoption of ASU 2020-06, the Company accounted for the 2019 Notes as a liability and equity component where the carrying value of the liability component was valued based on a similar debt instrument. In accounting for the issuance of the 2019 Notes, the Company separated the 2019 Notes into liability and equity components. The carrying value of the liability component was calculated as the present value of its cash flows using a discount rate of 4.5% based on comparative convertible transactions for similar companies. The carrying value of the equity component representing the conversion option was determined by deducting the fair value of the liability component from the par value of the 2019 Notes as a whole. The excess of the principal amount of the liability component over its carrying value amount, referred to as the debt discount, was amortized to interest expense on our consolidated statements of comprehensive income over the five-year term of the 2019 Notes. The equity component was not re-measured as long as it continued to meet the conditions for equity classification. The equity component related to the 2019 Notes recorded at issuance was $52.1 million, which was recorded in additional paid-in capital on the Company's consolidated balance sheets.

In accounting for the transaction costs related to the issuance of the 2019 Notes, the Company allocated the total costs incurred to the liability and equity components of the 2019 Notes using the same proportions as the initial carrying value of the 2019 Notes. Transaction costs related to the liability component were $7.4 million and are amortized to interest expense using the effective interest method over the five-year term of the 2019 Notes. Transaction costs attributable to the equity component were $1.6

million and are netted with the equity component of the 2019 Notes in stockholders' equity of the Company's consolidated balance sheets. Additionally, the Company recorded a net deferred tax liability of $11.4 million.

Effective January 1, 2022, the Company adopted ASU 2020-06. After adoption, the Company now accounts for the 2019 Notes, and any convertible debt issued going forward, as a single liability measured at amortized cost. As the equity component is no longer required to be split into a separate component, the Company recorded a net adjustment for the initial $50.4 million that was allocated to additional paid-in capital and $22.9 million of life-to-date interest expense recorded as amortization of debt discount. Additionally, the net deferred tax liability recorded for the 2019 Notes was reversed. The principal amount of the liability over its carrying amount is amortized to interest expense over the five-year term of the 2019 Notes. Since the 2019 Notes are classified as a single liability, there is no debt discount required to be amortized in 2022.

Contractual coupon interest expense related to the 2019 Notes was $1.0 million in 2023 and the Company recorded $1.8 million of amortization of the debt issuance costs related to the 2019 Notes as well. The effective interest rate on the 2019 Notes is 1.02%, which included the interest on the 2019 Notes and amortization of the debt issuance costs. As of December 31, 2023, the carrying value of the 2019 Notes was $69.5 million and the fair value of the principal was $109.8 million. The fair value of the 2019 Notes was determined based on the most recent trade activity of the 2019 Notes as of December 31, 2023.

The indenture governing the 2019 Notes contains customary terms and events of default. If an event of default (other than certain events of bankruptcy, insolvency or reorganization involving the Company) occurs and is continuing, the holders of at least 25% in aggregate principal amount of the outstanding 2019 Notes may declare 100% of the principal of, and any accrued and unpaid interest on, all of the 2019 Notes to be due and payable. Upon the occurrence of certain events of bankruptcy, insolvency or reorganization involving the Company, 100% of the principal of and accrued and unpaid interest, if any, on all of the 2019 Notes will become due and payable automatically. Notwithstanding the foregoing, the 2019 Notes provide that, to the extent the Company elects and for up to 360 days, the sole remedy for an event of default relating to certain failures by the Company to comply with certain reporting covenants consist exclusively of the right to receive additional interest on the 2019 Notes. The Company is not aware of any events of default, current events or market conditions that would allow holders to declare the principal of, and any accrued and unpaid interest on, all of 2019 Notes to be due and payable.