You Now Get Almost Nothing for Your Money, but It Could Be Worse

Chad Peterson, a TIAA spokesman, said CREF provides retirement accounts for “people in higher education, the nonprofit community, teaching hospitals” and the like.

Given a choice — and countless mutual fund companies, as well as TIAA, offer other money market funds that don’t seek to recoup these fees — I’d avoid this fund.

Mr. Crane says he would stay away from funds with the very highest yields. “Higher yield probably means higher risk,” he said. At the moment, he said, a yield of just 0.50 percent “is already in nosebleed territory.”

For a safe place to keep your cash, he suggested that you consider government money market funds, which, as the name implies, hold government securities. They are “golden in a deep crisis,” like the one that required Federal Reserve intervention in March, as well as back in 2007-8, Mr. Crane said. “Prime funds,” which can hold commercial securities, may be less liquid when the going gets rough.

But prime funds are a reasonable choice, too. They have been quite safe compared with mutual funds that hold stocks or bonds and often lose large amounts of money. Even in the worst case of the last 20 years, in which one fund lost money for investors, the losses amounted in the end to only 1 cent on the dollar. “That’s not a lot to worry about,” Mr. Lynagh said.

For even greater security, consider a bank account with Federal Deposit Insurance Corporation backing, which guarantees up to $250,000. Accounts from old-fashioned banks with brick and mortar branches, as well as higher-yielding online-only enterprises, carry F.D.I.C. insurance, and their rates are tracked by the website Bankrate.com. In periods of extremely low market interest rates, like this one, some online bank accounts have higher rates than money market funds do, reversing the typical relationship. The banks’ advantage may not last, but as long as the accounts are fully insured, there’s little risk in exploiting it.

Safety is the main issue, when you’re looking for a place to keep your cash.

“Don’t worry so much about the return on your money,” Mr. Crane said. ”Worry about the return of your money.”

It’s not easy to amass a cash fund these days. If you’re lucky enough to have done it, be sure to read the fine print. That will help you avoid losses, including negative interest.