BOSTON – Is it time to retire the idea of a 60/40 portfolio? The strategy has been generally regarded as a good starting point for most investors.

But many experts question whether a mix of 60 percent stocks and 40 percent bonds is suitable. Over the years, 60/40 has become a rough gauge for how to build adequate retirement savings without taking excessive risk. Typically, it's promoted as a sort of default portfolio balance for investors in their 40s, or even closer to retirement.

The basic rationale: Keep most of your retirement savings in the stock market, because stocks are likely to provide greater long-term growth than bonds. But when stocks fall, you'll want a significant percentage of your portfolio in bonds to cushion against steep losses.