<prompt> Human: I have a six month emergency fund, and many times that in investments. Largely post-tax index funds, which I can turn into cash in a couple days I shouldve put more into tax advantaged. Im living entirely off the returns on these investments.It recently occurred to me that I am unlikely to ever have an emergency that I cant pay for out of my investments, without even incurring taxes staying below the 0 long term capital gains tax threshold.So, whats my emergency fund for? When should I use it? Should I decrease its size down from six months of expenses to three months, to get better returns on that additional three months of expenses worth? Should I get rid of it all together, for the same reason?Any way I would use it, I think, essentially becomes timing the market. Which Ive had so thoroughly drilled into my head that I shouldnt do, and have formed strong habits around.For example, when Im selling off investments once a month, to pay for my expenses the following month, I could choose to skip it based on current market conditions, and pay the following months expenses out of my emergency fund instead. How would you make that kind of decision? Exactly where would you set the thresholds? 12 month performance? 3 month performance? My 3 month performance on most of my savings is currently at 3.13, due to the recent dip in the market. 5 year performance is 11.04. Is that reason enough to spend a months worth of expenses from my emergency fund, or... is there no point in me having an emergency fund?  <response>: So, whats my emergency fund for? An emergency.When should I use it?When you have an emergency.In all seriousness... your emergency fund is used for large, one off unexpected needs such as your car breaks down, your water heater stops working or a loved one dies and you want to fly out for the funeral. Or its used as a fall back measure if you lose your job or become disabled, you use it to pay the bills until disability kicks in or you find a new job.What you dont do is put it in a volatile market in the event that you actually need it on the same day it takes a nose dive.You put 3-6 months worth of expenses in a high yield savings account and you leave it alone. Everything else... everything above the 6 month expense mark, you can play with. Gamble it in the market, set your threshold at whatever you want for that money but your actual emergency fund should always be secured. 