The Crazy Christmas Week

Last week was an object lesson in why it's usually not wise to pay too much attention to the market's daily moves. Let's recap:

• Monday: In abbreviated Christmas Eve trading, the S&P 500 fell 2.7 percent, and the Dow dropped 600 points, its worst Christmas Eve ever.
• Tuesday: The markets are closed for Christmas.
• Wednesday: The biggest one-day percentage rise for all three indexes since March 2009; the Dow rises by 1000 points, its biggest point gain ever. 
• Thursday: The markets are down nearly 2 percent by 2 p.m., then reverse course to finish up by more than 2 percent.
• Friday: The markets waver all day before finishing up slightly. For all the drama, the S&P ends the week up 2.9 percent, and the Dow is up 2.8 percent.