<prompt> Human: So for the first time in my life I have started contributing to 401k around 1000month. I linger on this sub and most common advice I see is to buy Vanguard funds or Index funds to protect investment aka conservative less risky approach.However, it seems to me that Vanguard VTI is enjoying overall gain in SP index since last 3-4 years. Now, if stock market tanks and index drops by 50 hypothetical then how should I protect my principal at least 12kyear and forget about returns when it happens ?Any advice is appreciated.edit -- those who have seen 2000 dot com bubble, 2007 housing market crash , what did you do to protect 401kIRA andor other investment when market was bear driven.  <response>: Rule 1: Timing the market is bad.The only people that lost out in 2000 or 2007 are the ones who panicked and sold low. Then they saw the market going back up so they bought for even higher than they sold.Youre in this for the long haul. The market is always enjoying record highs because thats what the market tends to do. Set up your portfolio according to the risk you enjoy and keep at it. 