<prompt> Human: Im not sure if I understand correctly, given that there seems to be a caveat of how much of HSA savings must be kept in cash but each time I google that, I cant find any information, so Im going to go with the assumption that you can invest all your HSA savings into mutual funds? and if that assumption is wrong on all cases, please tell meIf theres a one-time 10 penalty for withdrawing typically, but the amount compounds regularly anyways, lets say at 15 for a specific mutual fund -- wouldnt a compounding HSA of 15 each year not to mention the pre-tax dollars compounding as well be worth the early withdrawal after, say, 10 years of compounding? That annual ROI would perform better than many stockssavings accounts each year, even when accounting for the tax rate after withdrawing and the 10 penalty?  <response>: Re: keeping a portion of your HSA in cash. It depends on the HSA provider. Theres no legal stipulation, but some providers require it. 