A timely reminder from WSJ as to whether we should stay put in the market, or not.

"The case can be made to do nothing" if you've got a well-thought-out mix of stocks and other securities in your portfolio, says Jason Graybill, senior portfolio manager at Abner, Herrman & Brock, an asset manager in Jersey City, N.J. And certainly stay on course if you are buying into the stock market in steady increments, such as through payroll deductions to your 401(k).

Beyond that, here are three reasons to be buying and an equal number to be selling:

Reasons to Buy

1. Quality Can Pay Off

Some professionals say this is a smart time to buy large-capitalization, high-quality stocks that tend to be fairly steady in price when the broader market is weak. Shares of giant companies with solid earnings prospects have lagged behind riskier investments until recently, and some of them are relatively cheap.

2. Economic Immunity

"The money that investors do have in the market should have a defensive tilt," says Brian Rauscher, director of portfolio strategy at Brown Brothers Harriman in New York. He favors companies that sell consumer staples -- such as personal-care products and drugs -- that consumers won't stop buying even if the economy slows.

3. Grab Those Sale Prices

Some already cheap stocks have gotten even cheaper. Jim Paulsen, chief investment strategist at Wells Capital Management in San Francisco, thinks downtrodden technology stocks could be the dark horse that actually helps lift the market back up.

Reasons to Sell

1. Trim Interest-Rate Plays

With the Fed having raised short-term interest rates from 1% in 2004 to 5% now, one thing investors should consider is the impact of higher rates on their stock investments.

2. Don't Get Greedy

If your investment in an area has ballooned over time because of big gains, consider trimming your position and pocketing the gains.

3. Listen to Your Stomach

If you've found the market's recent moves to be stomach-turning, you need to "realistically evaluate what your return expectations are and what your risk tolerance is," advises Mr. Graybill of Abner, Herrman & Brock.