NEW YORK (TheStreet) -- How will rising interest rates hurt your fixed-income investments? Many investors haven't had to worry about this question for years.

The Federal Reserve has kept interest rates at zero and the bull market in bonds has gone on for decades.  They have been told are "safe haven" investments. But that may change next month, if Fed policymakers pull the trigger and boost rates.

"The math just does not work in favor of the individual investor," said Stewart Taylor, a vice president at Eaton Vance, where he works as a portfolio manager and department strategist for the Diversified Fixed Income group. Taylor said there's an under-appreciation of the mathematics behind bond investing.

"If you own a 10-year Treasury [bond], or a 10-year corporate, it has, what we call in the business, a duration of 10 years. So that means for every 1% rates go up, the loss on that security will be 10%," he said.  Put another way, with the 10-year Treasury yielding 2.25%, an investor holding that Treasury note  would end up losing 8% on their investment.

Taylor said if rates go up 2%, you would then have an 18% loss. Taylor is a proponent of "laddering" your fixed-income investments. In other words, buying bond securities with maturity dates evenly spread out over several months or years, which enables investors to continuously reinvest their money in a way that allows them to take advantage of rate moves.

"Fixed income is not a bad place to hang out unless you're taking a lot of interest rate risk or duration risk," he said. "As long as you do things like corporate bond ladders from one year to five year, municipal ladders, or floating rate bank loans, for instance."

Taylor spoke at Camp Kotok, an annual gathering of economists and money managers in Maine.