I will chalk up SDREMGR's comments about who wants or has an emergency fund as coming from someone young and inexperienced with cash crunches.
Credit may not always be available to you, there may be delays in receiving unemployment if you lose your job, the stock market may be down 50 percent when you need the money, your tenants may file BK and the rent from your rental gets tied up in court, or a host of other problems could happen. While it's true that people living closer to the edge have more of a need for an ATM-accessible emergency fund, my experience has been that people with accessible cash reserves do better in cash crunches. And withdrawing from your 401k or IRA to meet a short term emergency costs you a lot of money in the long term.
I'm 36 so I'm not that old, but I have multiple properties that I own as well as a business that I own 100%. And I have never experienced any time that I needed emergency cash of more than $5k at any given day. And for those types of "emergencies" it's easily covered with a check or credit card. The worst "emergency" that I experienced was having to pay for a A/C for my office when it went down the day AFTER I closed escrow. Talk about timing. But other "emergencies" like a auto accident, broken down car, medical emergency, do not require cash. These issues are easily solved with a swipe of the credit card, and I have more than enough excess cash in the bank to pay for them within 30 days.
The whole idea of stashing a sum of money in a checking account, or savings account, separately as a sum of money that you would need immediate access to me is unnecessary.
I went through a 3 year period when I was starting up my business when I had to supplement the income I was paying myself from the business with my personal savings. I estimate that I went through about $20k during that period. I paid myself more as time went on and at around the 3 year mark, I was paying myself enough to offset my personal expenses. But that $20k didn't sit in my checking account, earning next to nothing. I had it in my stock brokerage account, in the market, which was a good thing, because those years were some good years.
The need for an "emergency cash" savings is due to financial shortsightedness and lack of true savings. Also, it may point to poor earnings potential or 100% dependence on a salaried job for income. I'm lucky to know that barring some economic meltdown, my business will net me about $10k+ each month so I don't have to worry about whether I will need some crazy cash for if I need emergency surgery due to an auto accident.
Again, there are only 2 types of "emergencies." One where you really need money in a hurry, for car trouble, medical bills, etc. And in most cases, those are easily covered by a credit card and withdraw of stocks from a brokerage account, or in my case, I just save less the following month and pay the credit card bills from my earnings of the next month.
The 2nd type is due to prolonged unemployment or lack of ongoing earnings. In those cases, you have unemployment to help soften the blow, and the negative shortfall should be easily supplemented by withdrawing from your stock portfolio on an as needed basis.
The possible 3rd type is catastrophic in nature, and you can't really plan for those. You are just F**ked. I'm talking a big accident and you can't walk or talk for life or something like that. Or at least you can't work for life. Then you are on government disability or you better have good family members who will take care of you.
Outside of those things, what else would you need "emergency savings" that can't be solved by "money savings?"