* Bank of America falls in premarket after results
* Best Buy down in premarket after holiday sales
* Initial claims data due
* Futures: Dow up 28 pts, S&P up 1.5 pts, Nasdaq off 3 pts
By Chuck Mikolajczak
NEW YORK, Jan 15 (Reuters) - U.S. stock index futures edged higher in choppy trading on Thursday, fluctuating between gains and losses, after the Swiss National Bank scrapped its three-year euro cap on the franc.
* Trading was volatile, as futures erased early gains after the SNB said it would discontinue the cap it introduced on Sept. 6, 2011 to fight recession and deflation threats.
* Bank of America lost 2.1 percent to $15.71 before the opening bell after the second-largest U.S. bank by assets reported a 14 percent slump in quarterly profit.
* Citigroup will report results Thursday, and Dow component Intel reports after the closing bell.
* Expectations for U.S. fourth-quarter earnings have fallen sharply in recent months, with growth now estimated at just 3.6 percent compared with an Oct. 1 estimate for 11.2 percent, according to Thomson Reuters data.
* U.S. stocks dropped for a fourth day Wednesday in volatile trading after a World Bank forecast added to worries about the health of the global economy.
* The benchmark S&P has fallen for three straight sessions and has declined in nine of the past 11 days. The index is down more than 3.8 percent from its last record high Dec. 29.
* Economic data due Thursday include weekly initial jobless claims, Empire State Manufacturing for January and the December producer price index for final demand at 8:30 a.m. (1330 GMT). The Philadelphia Federal Reserve Bank's reading on factory activity is due at 10:00 a.m. (1500 GMT).
* Best Buy shares tumbled 7.3 percent to $37 before the opening bell after the electronics retailer posted holiday sales results.
* European stocks dropped, weighed by Switzerland's blue-chip SMI index, which slumped more than 8.6 percent following the move by the Swiss National Bank.
* Asian shares rose after a rebound in oil and copper prices reassured investors.
Futures snapshot at 7:39 a.m. (1239 GMT):
* S&P 500 e-minis were up 1.5 points, or 0.07 percent, with 336,883 contracts changing hands.
* Nasdaq 100 e-minis were down 3 points, or 0.07 percent, in volume of 62,598 contracts.
* Dow e-minis were up 28 points, or 0.16 percent, with 76,863 contracts changing hands. (Editing by Bernadette Baum)