Many investors use "stable-value" funds inside of their 401k. These funds are also called "guaranteed investment contracts" or "GIC's." Essentially they are a basket of bonds backed by an insurance company or bank. These funds are not available inside of your IRA.

The Wall Street Journal questioned the stability of these funds this week.

How Stable Are They?

Many retirement-plan investors are turning to stable-value funds:

• The funds are designed to preserve capital and generate smooth returns. Contracts from banks and insurers help protect against sharp market swings.
• Investors should expect lower returns from the funds this year. They also may not have easy access to their balances after an employer bankruptcy or layoffs.

Many banks and insurance companies are growing reluctant to provide the "wrap" contracts that help smooth the funds' returns, leaving some stable-value managers scrambling to find alternatives.

And in certain cases where bankruptcies or massive layoffs have caused investors to yank money from a stable-value fund, some of them have been forced to wait months for their money. That's what has happened to former employees of retailer Mervyn's LLC. The bankrupt company terminated its 401(k) plan in October, but participants still can't get all their savings out of the plan because of withdrawal restrictions on the plan's stable-value fund.