A little decline here, a little setback there and, suddenly, you're talking about something serious. Such was the attitude Tuesday as the market's third-consecutive decline -- its biggest of the three -- generated discussion that the post-Oct. 9 rally may have ended. After trading as low as 8721.88 at about 12:30 p.m. EST, the Dow Jones Industrial Average closed down 1.3% to 8742.93. The S&P 500 shed 1.5% to 920.75 and the Nasdaq Composite lost 2.4% to 1448.96. Presumptive catalysts for the decline were some cautious comments from AOL Time Warner ( AOL), which fell 14.2%, and Nokia ( NOK), which lost 4.6%. Weak November sales data from Ford ( F) and General Motors ( GM) weighed on the automakers' shares, as well as traders' perception about the strength of consumer spending and the economy. Also contributing to the decline was a prevailing sense of foreboding. Many market participants sense that Monday's intraday highs of 9043 for the Dow, 954 for the S&P and 1521 for the Comp will prove to be the peaks of the post-October rally. Just one day after those peaks, technically inclined traders, such as RealMoney.com contributor James DePorre, are talking about the S&P having breached its Nov. 6 high of 925 and now facing a possible retest of support at 900. The market's propensity to accentuate the negative was further evinced in the strange case of Merck ( MRK), which traded as low as $55.16 before closing off 1.7% to $58.91. The decline began when Merck said it would have a conference call on Thursday in advance of its Dec. 10 scheduled analyst day. That news spurred concern Merck would warn, prompting a downgrade from Merrill Lynch to sell from buy. The resulting decline and scuttlebutt prompted Merck to issue a subsequent announcement reiterating its earnings guidance for the fourth quarter and 2003, which helped the shares recover from the intraday low. Meanwhile, the same Merrill analyst upped his recommendation to neutral.