Our portfolio of marketable securities is comprised of debt and equity securities that are classified as available for sale. Available for sale securities are presented on our consolidated balance sheets at fair value. Gains and losses resulting from the mark-to-market of these securities are included in “other comprehensive income.” Gains and losses are recognized in earnings only upon the sale of the securities and are recorded based on the weighted average cost of such securities.

In the three months ended March 31, 2011, we sold certain marketable securities for aggregate proceeds of $15,162,000, resulting in a net gain of $2,091,000

Below is a summary of our marketable securities portfolio as of March 31, 2012 and December 31, 2011.

		As of March 31, 2012							As of December 31, 2011
					GAAP		Unrealized					GAAP		Unrealized
		Maturity	Fair Value		Cost		Gain		Maturity	Fair Value		Cost		Gain
Equity securities:
	J.C. Penney	n/a	$	658,431	$	591,069	$	67,362	n/a	$	653,228	$	591,069	$	62,159
	Other	n/a		36,503		13,561		22,942	n/a		29,544		13,561		15,983
Debt securities		04/13 - 10/18		59,576		55,460		4,116	04/13 - 10/18		58,549		54,965		3,584
			$	754,510	$	660,090	$	94,420		$	741,321	$	659,595	$	81,726

We own 23,400,000 J.C. Penney common shares, or 11.0% of its outstanding common shares. Below are the details of our investment.

We own 18,584,010 common shares at an average economic cost of $25.75 per share, or $478,532,000 in the aggregate. As of March 31, 2012, these shares have an aggregate fair value of $658,431,000, based on J.C. Penney's closing share price of $35.43 per share. Unrealized gains from the mark-to-market of these shares are included in “other comprehensive income” and were $5,203,000 and $66,903,000 in the three months ended March 31, 2012 and 2011, respectively.

We also own an economic interest in 4,815,990 common shares through a forward contract executed on October 7, 2010, at a weighted average strike price of $28.86 per share, or $138,986,000 in the aggregate. The contract may be settled, at our election, in cash or common shares, in whole or in part, at any time prior to October 9, 2012. The strike price per share increases at an annual rate of LIBOR plus 80 basis points. The contract is a derivative instrument that does not qualify for hedge accounting treatment. Mark-to-market adjustments on the underlying common shares are recognized in “interest and other investment income, net” on our consolidated statements of income. In the three months ended March 31, 2012 and 2011, we recognized gains of $1,045,000 and $17,163,000, respectively, from the mark-to-market of the underlying common shares.

As of March 31, 2012, the aggregate economic net gain on our investment in J.C. Penney was $211,544,000, based on our economic cost of $26.39 per share.