(MoneyWatch) As of 3:15 p.m. Friday, stocks had risen 0.76 percent, with the S&P 500 up 12 points and the broader Wilshire 5000 up 0.8 percent. But the Dow Jones industrial average (DJIA) was down 16 points, or 0.1 percent. What gives?
The answer is simple: IBM. The Dow is comprised of only 30 stocks, but Big Blue counts for a full 10.94 percent of the index today. and in late trading activity was down 8.15 percent, or $16.88. If IBM had trounced earnings expectations, headlines likely would have have read, "Dow leads stock surge."
If the Dow were comprised of just the other 29 stocks, according to my calculations it would be up about 0.89 percent, or more than either the S&P 500 or Wilshire 5000.
The Dow is perhaps the most widely quoted market index, but it's not particularly reflective of the wider U.S. market. Total returns of the broadest stock indexes, like the Wilshire 5000, are far more indicative of overall stock returns.