2008 starts off with a thud -- bad omen or technical adjustment?

The Dow plummeted 221 points on its first trading day of 2008. Since nobody who knows what's moving the market on any given day will talk to the media, we are left to guess why it fell today. Four possible reasons:

• Bad news on the manufacturing front as the purchasing managers' index declined to 47.7 from 50.8
• Oil broke the psychologically painful $100 a barrel barrier due to a drop in supply and lingering geopolitical fears -- from violence in Nigeria to instability in Pakistan
• Gold hit a recent record of $860 an ounce
• The Dollar tumbled as the Euro rose to $1.47

Do any of these explanations account for the decline in the Dow or is it just portfolio managers taking some profits after clearing off some window dressing they took on so they could report to shareholders that they owned stocks that had done well in 2007?

I don't know the answer but reports I've been reading today suggest that there are tens of billions worth of bank write-downs and thousands of bank layoffs in the works. If a credit crunch is in the cards and oil prices keep rising, I think foreign oil stocks might be the place to look for investment profit in 2008.

Peter Cohan is president of Peter S. Cohan & Associates. He also teaches management at Babson College and edits The Cohan Letter.