(UPDATED, 1:30 p.m.) The U.S. stock markets declined for the third consecutive day, and they accelerated even as I wrote the first draft of this post.

and

have just about wiped out all gains since the year began (They

somewhat).

Try not to let it bother you.

If your exposure to the market is mostly via your IRA or 401(k), you should sit tight. Stick to your investment plan or philosophy. Try to avoid CNBC, tickers and other business media. This blog excepted, of course.

If you pull money out of the market now, you could essentially be committing the great investor sin of selling lower. This is especially true if you just got back into the market in the past six months after standing on the sidelines from late 2008 through most of 2009.

Granted, U.S. market indices are not at sub-March 2009 territory. The S&P 500 is still up

from its early March low. But a correction has been due for quite a while. The value of stocks compared to their companies' respective earnings potential were simply out of whack -- even if the correction isn't completely behind today's antics.

"We’ve been cautiously pessimistic about stock valuations for some time," said Jim Corbeau, a certified financial planner at Maas Capital Advisors in Portland. "However, this market drop is unrelated to valuations, and only tangentially related to the Greek fiscal crisis. It seems to be a case of trading programs taking over."

Wrote

:

McKay went on to quote Phil Roth, chief technical analyst at Miller Tabak: "This could be the thing that sets off a real correction, but we'll have to wait and see."

If you didn't plan for this correction over the past few months by rebalancing your allocations of stocks and bonds, or by harvesting profits from the recent rise in stock values and plugging them into bonds or money-market-like assets, you shouldn't necessarily take action now. Check yourself before you do. First, talk to someone --a friend or pro -- whose investment judgment you trust.

"If you can’t stomach the thought of a 3% (much less a 10%) drop in stocks, you shouldn’t have a material exposure to them," Corbeau said.

If you do make a move, make sure you're comfortable with what your portfolio's overall return since inception looked like at the end of 2009. Because that's about the point to where we've slid.

Feel free to disagree. But that's my "personal finance without the moodswings" advice.