Almost everybody knows there is risk in the stock market, a hard fact underscored by Monday's frightening plunge on Wall Street.

But with the financial crisis reaching epic proportions, people are starting to ask: How safe are my safe havens?

Here's a look at the most popular places people stash their cash: bank deposits, money funds and U.S. Treasury securities:

n Money market funds:

On Monday, the Treasury Department announced details of its plan to offer temporary insurance to money market funds. The plan is designed to stop the mass exodus from money funds that started after the Reserve Primary Fund became only the second money fund in history to "break the buck," or fall below $1 per share, on Sept. 19.

Money funds try to maintain a stable $1 per share, meaning shareholders should always get back at least what they put in.

With this new, temporary insurance plan -- if a fund participates -- the government will guarantee that if the fund breaks the buck, shareholders will still get $1 per share for balances they had in the fund on Sept. 19.

The plan is not open to individuals; only a fund can apply. To participate, funds should apply by Oct. 8 and pay a fee equal to 0.01 percent of the number of shares outstanding on Sept. 19. Funds that broke the buck before Sept. 19 cannot participate.

The insurance will expire after three months unless the Treasury secretary decides to extend the program for up to nine more months.

There is no per-person limit on how much money will be insured, like there is with insured bank deposits.

To see if your fund is participating ask your fund company.

The average yield on Treasury funds fell to 0.69 as of Sept. 23 from 1.10 on Sept. 16. General purpose funds were yielding 1.67 percent on Sept. 23, according to iMoneyNet.

On the other hand, average yields on tax-free money funds, which invest in short-term securities issued by state and local governments, have been soaring -- from 1.36 percent on Sept. 16. to 4.77 percent on Friday.

n Insured deposits

Deposit accounts at banks and thrifts are insured, up to certain limits, by the Federal Deposit Insurance Corp. The same goes for accounts at credit unions that are members of the National Credit Union Association (not all are). Both agencies are backed by the full faith and credit of the U.S. government.

Although the failure of a large bank could wipe out the FDIC's $45 billion insurance fund, the government agency could replenish it by drawing on a line of credit with the U.S. Treasury, which eventually would be repaid through banking-industry assessments.

"People who are worried about FDIC insurance are worried about the wrong things. We've cleared out the two biggest institutions people were worried about and it hasn't cost the FDIC a dime," says Greg McBride, senior financial analyst with Bankrate.com.

The basic deposit limits at insured banks, thrifts and credit unions are $100,000 per person per institution for regular accounts and $250,000 for most retirement accounts. There are ways to get additional insurance at the same institution by opening different types of accounts.

Deposit insurance covers savings and checking accounts, certificates of deposit and money market deposit accounts. It does not cover investments sold through a bank such as stocks, bonds, annuities or mutual funds including money market mutual funds.

n Treasury securities

For clients who want to protect a lot of money and don't want to open accounts at multiple banks, Peggy Cabaniss of HC Financial Advisors suggests buying Treasurys from the government by opening a Treasury Direct account at www.treasurydirect.gov. There is no fee to purchase and as long as you hold the securities to maturity, you will get your money back, assuming the federal government doesn't default or restructure its debt.

While still a remote possibility, it's not as inconceivable as it once was.