On July 19, 2019, the Company issued $287.5 million aggregate principal pursuant to the 2019 Notes, which includes 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. 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 2019 Notes will mature on July 15, 2024, unless earlier repurchased or converted in accordance with their terms.

During the third quarter of 2021, 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 fourth quarter of 2021, the quarter immediately following the quarter when the conditions are met, as stated in the terms of the 2019 Notes. These conditions have been met since the third quarter of 2020. As a result, $6,000 aggregate principal amount of the 2019 Notes have been converted by the noteholders since December 31, 2020. The conversions resulted in the issuance of a nominal number of shares of the Company’s common stock to the note holders, and the Company recorded a loss of approximately $1,000 and approximately $6,000 on the conversion of these notes, which is included in other expenses, net on our consolidated statements of

comprehensive income for the three and nine months ended September 30, 2021. The Company continues to classify the carrying value of the 2019 Notes as current liabilities on the Company’s consolidated balance sheet at September 30, 2021.

The net carrying value of the liability component of the 2019 Notes is as follows:



	September 30,			December 31,
	2021			2020
	(Amounts in thousands)
0.375% Convertible Senior Notes due 2024:
Principal amount	$	287,493		$	287,500
Unamortized debt discount		(30,793	)		(38,317	)
Unamortized debt issuance costs		(4,377	)		(5,446	)
Net carrying amount	$	252,323		$	243,737

Interest expense recognized on the 2019 Notes for the three months ended September 30, 2021 was $0.3 million, $2.5 million and $0.4 million for the contractual coupon interest, the accretion of the debt discount and the amortization of the debt issuance costs, respectively. Interest expense recognized on the 2019 Notes for the nine months ended September 30, 2021 was $0.8 million, $7.5 million and $1.1 million for the contractual coupon interest, the accretion of the debt discount and the amortization of the debt issuance costs, respectively. The effective interest rate on the 2019 Notes is 5.1%, which included the interest on the 2019 Notes, amortization of the debt discount and debt issuance costs. At September 30, 2021 and December 31, 2020, the carrying value of the 2019 Notes was $252.3 million and $243.7 million, respectively, net of unamortized discount, and the fair value of the 2019 Notes was $732.9 million and $501.0 million, respectively. The fair value of the 2019 Notes was determined based on the most recent trade activity of the 2019 Notes at September 30, 2021.