NEW YORK (AP) - The last time the stock market had this long of a winning streak, Twitter shares weren't even a part of it yet.
Yet another gain for stocks Thursday sent the Standard & Poor's 500 index higher for an eighth straight day, its longest winning streak since July 2013, which was months before Twitter shares started trading publicly. It's the latest step higher for a market that's methodically climbed to record after record for much of this year as both the economy and corporate profits have improved.
The S&P 500 rose 14.33 points, or 0.6 percent, to 2,552.07. The Dow Jones industrial average gained 113.75, or 0.5 percent, to 22,775.39 and the Nasdaq composite rose 50.73, or 0.8 percent, to 6,585.36. All three indexes added to their records set a day earlier, again.
All those moves higher actually have some professional investors a bit nervous, because even the healthiest markets tend to have some sharp sell-offs from time to time. The last time the S&P 500 had a pullback of just 5 percent was more than a year ago.
"What's really troubling most people more than anything is that we just go straight up," said JJ Kinahan, chief strategist at TD Ameritrade. "There hasn't been a pullback. That's what most on Wall Street are trying to come to grips with."
Encouraging reports on the economy have been helping stocks, and on Thursday, they included a stronger-than-expected rebound in U.S. factory orders during August and a drop in the number of workers applying for unemployment benefits last week