The Company’s equity and debt securities consisted of the following:


	March 31, 2022
	Amortized Cost Basis			Unrealized Gains		Unrealized Losses			Aggregate Fair Value
	(in thousands)
Equity securities:
Long-term
Investment in private equity securities	$	15,000			—		—			15,000
Total equity securities		15,000			—		—			15,000
Available-for-sale debt securities
Short-term
Corporate debt securities		111,981			9		(818	)		111,172
Money market accounts		105,415			—		—			105,415
U.S. government debt securities		110,594			—		(702	)		109,892
Municipal bonds		5,062			—		(33	)		5,029
Yankee debt securities		5,983			—		(31	)		5,952
Less: Cash equivalents		(105,415	)		—		—			(105,415	)
Total debt securities due within 1 year		233,620			9		(1,584	)		232,045
After 1 year through 5 years
U.S. Government debt securities		216,936			5		(4,931	)		212,010
Corporate debt securities		194,432			—		(5,771	)		188,661
U.S. agency debt securities		69,959			—		(2,466	)		67,493
Municipal bonds		12,422			—		(255	)		12,167
Yankee debt securities		6,161			—		(215	)		5,946
Total debt securities due after 1 year through 5 years		499,910			5		(13,638	)		486,277
After 5 years through 10 years
Municipal bonds		7,085			—		(180	)		6,905
Redeemable preferred stock investment		20,000			—		(2,391	)		17,609
Total debt securities due after 5 years through 10 years		27,085			—		(2,571	)		24,514
Total available-for-sale debt securities		760,615			14		(17,793	)		742,836
Total equity and debt securities	$	775,615		$	14	$	(17,793	)	$	757,836


	December 31, 2021
	Amortized Cost Basis			Unrealized Gains		Unrealized Losses			Aggregate Fair Value
	(in thousands)
Equity securities:
Short-term
Bond funds	$	99,314		$	—	$	(515	)	$	98,799
Exchange traded funds		35,174			—		(174	)		35,000
Total equity securities		134,488			—		(689	)		133,799
Available-for-sale debt securities
Short-term
Corporate debt securities		92,116			24		(148	)		91,992
Money market accounts		77,067			—		—			77,067
U.S. government debt securities		51,318			—		(81	)		51,237
Municipal bonds		4,980			—		(12	)		4,968
Yankee debt securities		3,615			—		(6	)		3,609
Less: Cash equivalents		(77,067	)		—		—			(77,067	)
Total debt securities due within 1 year		152,029			24		(247	)		151,806
After 1 year through 5 years
Corporate debt securities		242,421			29		(1,913	)		240,537
U.S. Government debt securities		147,699			7		(786	)		146,920
U.S. agency debt securities		70,069			—		(535	)		69,534
Municipal bonds		11,920			13		(11	)		11,922
Yankee debt securities		8,633			—		(89	)		8,544
Total debt securities due after 1 year through 5 years		480,742			49		(3,334	)		477,457
After 5 years through 10 years
Municipal bonds		7,633			—		(43	)		7,590
Redeemable preferred stock investment		20,000			1,965		—			21,965
Total debt securities due after 5 years through 10 years		27,633			1,965		(43	)		29,555
Total available-for-sale debt securities		660,404			2,038		(3,624	)		658,818
Total equity and debt securities	$	794,892		$	2,038	$	(4,313	)	$	792,617

Gross unrealized losses on the Company’s equity and debt securities were $17.8 million as of March 31, 2022. Gross unrealized losses on the Company’s equity and debt securities were $4.3 million as of December 31, 2021. During the first quarters of 2022 and 2021, the Company did not recognize any credit losses.

The Company’s securities of $492.4 million are used as collateral for an outstanding margin account borrowing. As of March 31, 2022, the Company had an outstanding borrowing of $15.0 million under its margin account. Margin account borrowings were used for the purchase of real property located in El Monte, California in 2020.