Vanguard Total Market Index or Vanguard SP500 Index (equities), and Vanguard Total Bond Index. Just decide on an allocation (like 30% equities and 70% for someone around age 70, or maybe 40% bonds and 60% equities), then buy and hold for the rest of your life, ajusting the bond allocation upward as you get older. Just an idea for a simple portfolio of 2 mutual funds.