The panicked selloff in the stock market last week left investors' jangled nerves further on edge.

It also exacerbated worries that have grown as the credit crisis that exploded last month shows signs of worsening.

Many investors are wondering how much lower it could go and how vulnerable are their holdings in stocks, CDs and other investments as the credit crisis continues.

The Associated Press addresses some of the concerns with answers to common questions, based on interviews with experts.

Q. Where's the best place to keep short-term money?

Much like your overall portfolio, you might want to consider diversifying even your cash reserves. Right now, for example, rates on tax-free money-market mutual funds are better than certificates of deposits, or CDs.

To find the best rates for CDs and money-market deposit accounts, check Bankrate.com, which includes listings from online banks.

If you've got cash to invest for the long-term – at least 10 years – putting a little in the market in stages might not be a bad idea, said Lisa Kirchenbauer, president of Kirchenbauer Financial Management & Consulting in Arlington, Va.

Q. What should investors nearing retirement do when they see their portfolio's value declining so sharply?

“If your portfolio is way down, you don't want to start withdrawing from it when the market is in a trough, because you'll just be making things a lot worse,” said Christine Fahlund, vice president with T. Rowe Price.

If you're near retirement, you may want to fight your instincts to retreat. “If you can afford it, consider increasing retirement contributions in the final years of your working life,” Fahlund said. “You'll be taking advantage of the market conditions, and buying into the market when it's low.”

Amid volatile markets, Fahlund said those close to retirement must become increasingly flexible about their plans, from deciding when to stop working, to how much money to set aside for retirement, and how much to spend. Soon-to-be retirees should avoid setting rigid plans if they don't have to.

Q. How should investors whose college funds have taken a hit respond?

The issue comes down to two factors: risk tolerance and time horizon, said Alan Gayle, director of asset allocation and senior investment strategist for Atlanta-based RidgeWorth Capital Management. “If the portfolio that they own is keeping them up at night, then that's a signal that they need to make some adjustments,” he said.

The date for when the child is going to school plays a key role in the broader answer. Investors should reduce a college fund's exposure to the stock market as the student's enrollment date approaches. However, if the parents have at least three to five years before they are going to need those funds, Gayle said, the overall evidence suggests stocks are relatively cheap at the moment.

Q. How will I know when the market's hit a bottom?

Not until after it has recovered off the lowest point. Not even the smartest experts can predict when the market will turn.

Economist Peter Morici, professor at the University of Maryland School of Business, says he doesn't foresee a turnaround this year.

The signs to watch for indicating a market bottom, he says, are when banks lend freely again and the housing market turns upward.