Investors have driven down the Dow Jones Industrial Average, a barometer for the largest U.S. stocks, to less than 10,000 for the first time since November 2004. Some focused mutual funds that hoard the big-volume stocks have tied their fortunes to the ups and downs of these companies. Eleven of the 13 stocks mentioned in this article, averaging a trading volume of more than $1.5 billion over a recent five-day period, are members of the Dow. If you are trying to limit exposure to any of them, the associated funds might not be for you. One of the two non-Dow stocks, Apple ( AAPL), averaged $7.19 billion in trading volume over the five trading days last week. No other U.S. common stock had a higher dollar volume of trading. And, with 26.8% of the Fidelity Select Computers Portfolio ( FDCPX) assets tied up in Apple shares, no other company has a larger impact on the performance of this fund. General Electric ( GE) is the second most actively traded, at an average daily dollar volume of $4.89 billion. It's the top holding of the Vanguard Industrials Adm Fund ( VINAX), accounting for 16.4% of assets. The top three stocks hoarded by the Banks UltraSector ProFund ( BKPIX) made the list, with $3.6 billion in activity in Citigroup ( C), $3.1 billion in JPMorgan Chase ( JPM) and $2.77 billion in Bank of America ( BAC). Two other technology stocks made the cut. Microsoft ( MSFT), at 14.30%, is the top holding of Fidelity Select Software & Computer Services Portfolio ( FSCSX). And Intel ( INTC) dominates the Semiconductor UltraSector ProFund ( SMPIX), at 34% of assets. With everyone worried about the economy, having Procter & Gamble ( PG), a consumer non-cyclical stock, as the biggest holding of the Consumer Goods UltraSector ProFund ( CNPIX) makes good sense.