Note 7 - Cash and Due from Banks >. Note 8 - Investment Securities Held For Trading >. Note 9 - Investment Securities Held To Maturity >. The Corporation is required by law to maintain minimum average reserve balances. The amount of those reserve average balances was approximate- ly $46,078,200 at December 31, 2001 (2000 - $45,107,600). At December 31, 2001 and 2000, there were no securities held for trading purposes or options on such securities. All trading instruments are subject to market risk, the risk that future changes in market conditions, such as fluctuations in market prices or interest rates, may make an instrument less valuable or more onerous. The instruments are accounted for at market value, and their changes are reported directly in earnings. The Corporation may write options on trad- ing securities as part of its trading activities. Also the Corporation may enter in transactions of securities sold not yet purchased for trading pur- poses. These transactions are carried at market value. Net gains and loss- es resulting from these transactions are recorded in the trading income or loss account. The net gain from the sale of trading securities amounted to $419,367 for the year ended December 31, 2000 (a loss of $7,946 for 1999), and were included in earnings as trading income. No net revenue from the sale of trading securities was recorded during the year 2001. The amortized cost, gross unrealized gains and losses, approximate market value, weighted average yield and maturities of investment securities held to maturity at December 31, 2001 and 2000 were as follows: First BanCorp.> 2001 0 62 Expected maturities of mortgage backed securities and certain other secu- rities might differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. At January 1, 2001, in connection with the adoption of SFAS No. 133, the Corporation transferred a portfolio of $207 million of GNMA cer- tificates held to maturity into the available for sale category. The unrealized gain of $994,500, net of taxes, was reflected in other comprehensive income as a cumulative effect of the change in accounting principle. The Corporation does not expect reclassification of the transition adjustment included in other comprehensive income within the next twelve months. December 31, 2001 December 31, 2000 Weighted Weighted Amortized Unrealized Market average Amortized Unrealized Market average cost gains (losses) value  yield% cost gains (losses) value yield% (Dollars in thousands) Obligations of U.S. Government Agencies: After 1 to 5 years $ 10,000 $ (12) $ 9,988 7.04 After 10 years $211,194 $ 3 $(6,466 $204,731 7.39 90,176 $1,412 (5,191) 86,397 7.53 Puerto Rico Government Obligations: After 1 to 5 years 5,000 5,000 5.00 After 10 years 4,084 228  4,312 6.50 3,831 (56) 3,775 6.50 United States and Puerto Rico  Government obligations $220,278 $231 $(6,466 $214,043 7.32 $104,007 $1,412 $(5,259) $100,160 7.44 Mortgage backed securities: GNMA certificates After 10 years $206,989 $1,465 $ (139) $208,315 6.94 Corporate bonds: After 1 to 5 years $ 64,018 $ (277 $ 63,741 3.49 Total Investment Securities Held to Maturity $284,296 $231 $(6,743 $277,784 6.46 $310,996 $2,877 $(5,398) $308,475 7.11 ) ) ) )