<prompt> Human: Im slightly confused at what I should do. Currently, I have in the sp 500 through our fidelity 401k which has returned 16 YTD at an expense ratio of .03.However, I see that our large cap growth funds are returning 30 YTD w an expense ratio of .3 which isnt ridiculously high.However, I do know that conventional wisdom is that .3 and .03 over 30-50 years is a big deal but what if the returns are really high?Question is: Do I just stick with what I have with constant returns at 15 w .03 expense ratio or do some re-investments? Are higher returns worth the higher expense if at the end of the day the net seems to be higher?  <response>: The entire point is that returns cant be promised, while expenses are. Whatever return you see is always based on past performance and never indicative of future performance. 