<prompt> Human: Over the past few months, the growth rate on my 401k has been steadily growing, from 5, now its over 9. Its in a year 2050 targeted retirement mutual fund with very diverse portfolio, but right now a large chunk of it is in USA stocks. The stock market has been having a lot of growth recently, which has increased the value of my 401k.But knowing that the stock market increase can have this big of an effect makes me a bit worried about the bubble bursting, and reversing all the gains that its recently given. I am wondering if it would be wise to try to shift the funds to a different portfolio with slightly less emphasis on the stock market.  <response>: If youre in a 2050 fund that means youre relatively young and a crash tomorrow means pretty much nothing for you. You dont need this money for 33 years, what the market does now is irrelevant. Just leave it alone. 