3. Investments 4. Securities Available for Sale 5. Loans Held for Sale Loans held for sale consist of the following: Gross gains of $11.5 million and $863,000 were recognized on sales of securities available for sale during 2002 and 2001, respectively. There were no sales of securities available for sale in 2000. Mortgage-backed securities aggregating $867.7 million were pledged as collateral to secure certain deposits and borrowings at December 31, 2002. See Notes 12 and 13 for additional information regarding securities pledged as collateral to secure certain borrowings. Securities available for sale consist of the following: The carrying values and yields on investments at December 31, 2002, by contractual maturity, are shown below: (1) Balance represents FRB and Federal Home Loan Bank (“FHLB”) stock, required regulatory investments. The carrying values of investments, which approximate their fair values, consist of the following:  At December 31,  (In thousands) 2002 2001 Federal Home Loan Bank stock, at cost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $128,855 $131,181 Federal Reserve Bank stock, at cost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23,999 23,847  Interest-bearing deposits with banks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 868 914 $153,722 $155,942 Carrying (Dollars in thousands) Value Yield Due in one year or less . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 868 1.57% No stated maturity (1)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152,854 4.49 $153,722 4.47 At December 31, 2002 2001 Gross Gross Gross Gross Amortized Unrealized Unrealized Fair Amortized Unrealized Unrealized Fair (Dollars in thousands) Cost Gains Losses Value Cost Gains Losses Value Mortgage-backed securities: Federal agencies . . . . . . . . $2,341,549 $ 73,225 $ (35) $2,414,739 $1,547,374 $ 11,691 $ (979) $1,558,086 Private issuer and collateralized mortgage obligations . . 12,178 4 (877) 11,305 26,828 90 (993) 25,925 Other securities . . . . . . . . . . 750 – – 750 650 – – 650 $2,354,477 $ 73,229 $ (912) $2,426,794 $1,574,852 $ 11,781 $ (1,972) $1,584,661 Weighted-average yield . . . . . 5.96% 6.55% At December 31, (In thousands) 2002 2001 Residential mortgage loans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $277,395 $286,552  Education loans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199,080 165,057  $476,475 $451,609  page 54