The stock market has momentum, fund managers have performance anxiety and nothing else matters, to quote Metallica . Certainly, a raft of worse-than-expected economic data, cautious comments from Intel ( INTC) CEO Craig Barrett and disappointing results from Target ( TGT) didn't much matter on Thursday. Traders eagerly bought the intraday dips following those of the past two sessions. At day's end, the Dow Jones Industrial Average was up 0.8% to 8713.44, the S&P 500 higher by 0.8% to 946.67 and the Nasdaq Composite up 1.1% to 1551.38. At 1.5 billion shares on the New York Stock Exchange and nearly 2 billion in over-the-counter activity, volume was up from the previous two days, a bullish sign. Breadth was positive, although not wildly so, and while 251 Big Board names hit new 52-week highs, only 44 Nasdaq stocks pulled the trick. Some of the buying was ostensibly due to cautiously upbeat comments from IBM ( IBM) CEO Sam Palmisano -- Big Blue gained 1.1% -- and a bullish spin on the mostly woeful economic reports (more on that below.) Mostly, it seems as if stocks went up because they've been going up. Folks previously underweight equities or on the sidelines piled into what's been working lately for fear of missing the next big up move. This is commonly known as performance anxiety. "Fortunately, we had begun to reduce cash in March as reported here on expectations of a technical bounce," Brett Gallagher, who overseas about $400 million as head of U.S. equities at Julius Baer Asset Management, wrote in a midquarter update Wednesday. "We did not, however, change the low Beta associated with our portfolio holdings -- we may have to." I added the emphasis, but that's a pretty dramatic statement sans italics, as Gallagher seems to be saying: "We sat out the run-up in tech, biotech and speculative small-caps, but we can't afford to miss those kinds of (potential) capital gains any longer."