The Bogleheads' Guide to Investing

Mr. Bogle suggests that owning your age in bonds is a good starting point. So, a 20-year-old would hold 20 percent of his/ her portfolio in bonds. By the time this investor reaches 50, the bond portion of the portfolio would have gradually increased, in 1 percent increments, to now represent 50 percent of his portfolio. Increase your percentage of bond holdings if you are a more conservative investor, and decrease your percentage of bond holdings if you want to be more aggressive with your portfolio.