<prompt> Human: If a person properly saved for retirement in an SP Index fund as Buffett suggests, why have any bonds? Historical data on the SP shows when it dips, it comes right back. Also when they say this, do they mean bonds or a bond index such as VBMFX?  <response>: Historical data on the SP shows when it dips, it comes right back.Comes right back is different when youre 70 vs. when youre 30.At 30, you can wait 2-5 years. At 70, youre pulling money regularly that will not sit in the market long enough to come right back. If the market drops 40 when youre 70, you still have to pull out money to survive. That hurts the value of your nest egg significantly.Its easier to handle volatility during your working years than during retirement. 