<prompt> Human: Basically, I have cancelled all my credit cards - All I have now is an AMEX green card. These are different since you MUST pay them off at the end of each month. Since you cannot carry a balance on it, there is no interest to pay. All of my extra cash at the moment is going into an investment account and I use that to purchase ETFs. The ETFs usually have a hold requirement of about 30 days until you can sell without penalty. Aside from that, the cash is pretty liquid and can be pulled out within about 3-5 days if needed. This account has more than 6 months of living expenses in it currently.Solution: my AMEX green card has no limit. I charge the emergency to it and pay it off when I can move the funds around. Added bonus: 1 Rewards. Any seriously huge payment would need to be cleared with them, but thats only a 5 minute call and they are generally very pleasant to work with. Note: I know there are better reward cards, but this has no limit or fee and has a flat 1 Reward rate across the board - about as no-nonsense as it gets.I know there is always the wildcard of weather or not the vendor I will need to pay accepts AMEX or not, but I feel that anything I would deem an emergency Insurance deductible, Hospital bill, Flight home... will have no problem taking AMEX. From my research experience, this is generally the case. I know many debt payments wont take credit, but I dont view any debt as an emergency -- I know you cant usually pay bail with an AMEX, though I figure whatever ridiculous situation that would require me to pay bail could allow for a few days to get the money... I mean, its jail. No ones going anywhere. Haha...Seriously, though, I feel like this is a happy medium between having your money work for you and being ready should the situation require it.If something does occur, I can simply pay it with my AMEX move the money around in my investment account in order to pay the bill. Since I have the billing cycle as lead time, I feel like this gives me plenty of time to move the money around penalty-free. This goes without saying, most of the ETFs I have bought are already past their hold requirement, so they are pretty liquid.I also really dont use this card outside of normal usage Though, I try to funnel as many purchases through it as possible to get the rewards. So I am not worried about overspending. I am pretty disciplined already.I know the idea of a credit card as an emergency fund sends shivers down most PF readers spines, but I dont feel this is the same and I cannot really see much of a downside to outweigh the gains I will be making on the money...I would appreciate comments or feedback!EDIT: Some good and some negative feedback. Totally cool.A couple of points to clarify: AMEX does charge 95, but thats after 1 year. I forgot to include that - I put about 30kyr on it, so thats not a big deal, the points easily cover that. I also have 10 in an ESPP, 6 in a matched 401k, 5500yr in a Roth IRA as well... This wasnt a question about an overall savings plan insomuch as it was looking for flaws in my EF idea. Some really good input regarding the types of funds -- I am a pretty aggressive investor, since I have a bunch of risk tolerance. You guys are right, the ETFs dont all have to be stock market. Perhaps put more in Bond ETFs? I generally have 1 month or so in checking just as a matter of course - that fluctuates from time to time, but a couple thousand is generally hanging out in checking at any given time.I think the takeaway is basically; focus on more stable assets for the EF.EDIT 2: The layoff question came up -- If I get laid off, my living expenses equal about 35 of my total gross income. Unemployment would more than cover that until I could find something else.  <response>: Using a credit card as an intermediary for emergency funds is fine; I myself would float emergency expenses on a credit card until the next statement balance for the 1.5 back.What worries me is your use of an exchange-traded fund to hold your emergency money. Depending on what youre invested in, your money could lose value when you need it the most. This is why we recommend keeping emergency fund money in a federally insured vehicle like a savings account, or I-Bonds if you understand the short-term restrictions on redemptions. 