	Effective Rate			Coupon Rate			Outstanding
Maturity (Dollars in Millions)	Effective Rate			Coupon Rate			October 31, 2020			February 1, 2020			November 2, 2019
2023		3.25	%		3.25	%	$	350		$	350		$	350
2023		4.78	%		4.75	%		184			184			184
2025		9.50	%		9.50	%		600			—			—
2025		4.25	%		4.25	%		650			650			650
2029		7.36	%		7.25	%		42			42			42
2033		6.05	%		6.00	%		113			113			113
2037		6.89	%		6.88	%		101			101			101
2045		5.57	%		5.55	%		427			427			427
Outstanding unsecured senior debt								2,467			1,867			1,867
Unamortized debt discounts and deferred financing costs								(17	)		(11	)		(11	)
Unsecured senior debt								2,450			1,856			1,856
Effective interest rate								5.90	%		4.74	%		4.74	%

Our unsecured senior long-term debt is classified as Level 1, financial instruments with unadjusted, quoted prices listed on active market exchanges. The estimated fair value of our unsecured senior debt was $2.6 billion at October 31, 2020, $2.0 billion at February 1, 2020, and $2.0 billion at November 2, 2019.

In March 2020, we fully drew down our $1.0 billion senior unsecured revolver. In April 2020, we replaced and upsized the unsecured credit facility with a $1.5 billion senior secured, asset based revolving credit facility maturing in July 2024. The revolver is secured by substantially all of our assets other than real estate, and contains customary events of default and financial, affirmative, and negative covenants, including but not limited to, a springing financial covenant related to our fixed charge coverage ratio and restrictions on indebtedness, liens, investments, asset dispositions, and restricted payments, including a restriction on dividends in 2020 if our outstanding borrowings under the credit facility exceed $1.0 billion. Outstanding borrowings under the credit facility bear interest at a variable rate based on LIBOR plus the applicable margin. In October 2020, we fully repaid the $1.0 billion outstanding balance on our revolver and have the full $1.5 billion available for utilization. No amounts were outstanding on the credit facility in place as of October 31, 2020, February 1, 2020 or November 2, 2019.

In April 2020, we issued $600 million of 9.50% notes with semi-annual interest payments beginning in November 2020. The notes include coupon rate step ups if our long-term debt is downgraded to below a BBB- credit rating by S&P Global Ratings or Baa3 by Moody’s Investors Service, Inc. The notes mature in May 2025. We used part of the net proceeds from this offering to repay $500 million of the borrowings under our senior secured, asset based revolving credit facility with the remaining net proceeds available for general corporate purposes.