Desperate for richer yields on their portfolios, individual investors have thronged in recent years to mutual funds promising higher-than-usual income. The question is: Do these investors understand the higher-than-usual risks involved?

The answer is probably no. That’s because in the riskier funds, not all the perils are disclosed. Moreover, even when risks are formally discussed, many investors may still not realize how the funds really work. Trading on nonpublic information, for example, is a common practice in some of the instruments these funds hold.

Inspecting high-yielding mutual funds for potential pitfalls is always worthwhile. It is even more so now, with the Federal Reserve Board poised to make its first interest rate increase in over nine years.

Given the exotic investments that some income funds hold, understanding their risks is especially crucial. I’m talking about so-called leveraged loans or bank loans found in floating-rate income funds.