Stocks in the U.S. look expensive and bond yields remain paltry, leaving investors with a quandary: Where should they go for diversification and a shot at greater returns?

Wandering off the beaten path almost invariably leads to taking more risk, seeing bigger swings in value and, sometimes, higher fees.

But financial advisers say that isn’t necessarily bad—as long as these bets remain a small part of your portfolio, and you understand what could go wrong and are prepared to lose your money.

Here is a look at five options that are generally available to a broad swath of the public. Some of these investments shouldn’t represent more than 1% of your portfolio, experts say. Others might account for more, alone or in combination, but make sure that steep losses or difficulties liquidating the investments wouldn’t threaten your retirement savings, your standard of living or your other financial goals.

Peer-to-Peer Lending

Lending money to someone who is making home improvements or trying to pay down a credit-card bill can pay off better than buying a bond issued by a large corporation, let alone the federal government. That isn’t a surprise—the risk of default is likely far higher.