Chug an extra cup of coffee. Run an extra 20 minutes on the treadmill. Whatever it takes, don't fall asleep right now. Because the stock market is trying to lull us again.

Three weeks have now passed since the market's January 22 low. And, despite a couple of rough days last week, stocks have generally "held it together." Including today, the Standard & Poor's 500 index has ended in the plus column nine out of the past 15 trading days -- a respectable run, though hardly a barnburner.

The risk is that, after another week or two of generally rising prices, the market could roll over again in late February or early March. I'm not necessarily predicting such an outcome -- simply cautioning you to be on the lookout.

The January bottom was a pretty good one, but it lacked certain technical characteristics that have signaled every major low of the past 50 years. Normally, for example, key momentum gauges will bottom a few days to a few weeks before the indexes. This time, the bottom for price as well as for most rate-of-change indicators occurred the same day.

There's always a chance, of course, that "this time is different." More likely, though, the S&P will revisit its January low (1310) at some point, and even break through it by at least a marginal amount.

Meanwhile, I advise you to be very cautious with new purchases. Yesterday, American International Group (NYSE: AIG), the world's largest insurance company, disclosed that it had underestimated its losses in October and November from insuring mortgage-related instruments by about $4 billion.

AIG will recover from this setback, as will other businesses that fell victim to similar underestimations. I'm not saying it's going to happen tomorrow, but it will happen.

Stay tuned.

Many of my Profitable Investing subscribers are getting a bit weary of the mediocre numbers their retirement accounts have cranked out over the past two years. Is now the time to spice things up -- say, by adding a small-cap mutual fund to the mix?

My answer, brief and direct: Not yet. I can certainly understand their frustrations. After all, for the two years ended January 31, an account divided between a government bond fund, a U.S. stock index fund and an international stock index fund should have returned about 7% annually. That's pretty slim pickings compared with the bountiful harvest we grew accustomed to in the 1990s. But it's still a positive return, with only a modest degree of risk.

If I were to make any suggestion, it would be to consider switching out of the government bond fund and into a guaranteed fixed account. (Many retirement-plan sponsors offer this option.) However, I would hold off making even this move until the 10-year Treasury yield dips back to 3.6%.

The tenner closed at 3.86% today. Chances are, we'll see it back at 3.6% (or even a tad less) when the stock market gets around to "testing" its January low, probably sometime in the March to May time frame.

What about the small-cap idea? Too risky right now. Despite occasional bounces, small caps have lagged their blue chip brethren since April 2006. I wouldn't mind shoveling some money into small caps once I'm reasonably sure the market has made a solid bottom. For the time being, I'll probably stick with relatively large, household name companies.

For traders, I'm beginning to smell an opportunity to play the market's next (and, let's hope, last) leg down. Ideally, the Standard & Poor's 500 index should climb above its February 1 high of 1395, and then stall. That would be our signal to probe the short side, most likely through put options on the S&P index itself. Stay tuned!