This is part of a series of columns by retirement expert Dan Solin. Please bring him your questions in the comments box and he will answer as many as he can.

Is this a good time to invest, or should you sit on the sidelines until the market has "bottomed out"? This is the most common question I am asked.

It would be great if there was a way to tell when the market had reached its low. If you could do this, you would be able to buy stocks when the markets were taking off and retreat to risk-free investments, like cash and Treasury bills, in down markets.

Unfortunately, the data on timing the markets is very dismal.

One large study looked at more than 15,000 predictions by 237 market timing newsletters over a 12-year period. At the end of the period studied, 94.5% of the newsletters went bust. Not very impressive.

The financial media likes to hype stories suggesting that the markets are tanking or are poised for a rebound. These predictions are usually inaccurate and generally unreliable.

Here's a better question for you to consider: Should you be in the markets at all?