NEW YORK (Reuters) - Stocks dropped on Monday, pulling back from gains in the prior session that left the S&P 500 at a five-year high and the Dow above 14,000, as factory orders data disappointed and worries about the euro zone crisis resurfaced. The S&P 500 was on track for its biggest daily percentage decline since December 28. Chevron and Wal-Mart were among the biggest drags on the Dow after analyst downgrades. "The market is due for a pullback. That's not really a surprise. ...