Well, basically this is very important that having an emergency fund is very important for a Invest. When you invest in Bitcoin at a fixed price and then if the market falls, you can use that emergency fund for any necessary purpose. It is important to collect an emergency fund before buying Bitcoin, it will always be a good plan for yourself and it can benefit the investor in any bad time. I think such a plan would be a good step for real investors where they invest according to a percentage, save some percentage and leave some for an emergency fund. Many times this emergency fund is very useful to deal with emergencies, every person should have such an emergency fund plan that will always benefit them.
Facing unexpected situation is inevitable as humans so setting an emergency fund is good, in bitcoin investment emergency fund is not meant for buying bitcoin rather to settle unexpected expenses when they arise without thinking of selling our bitcoin you can use your Discretionary income to buy bitcoin, also trying to fix up with your emergency fund before buying isn't necessary you can still be buying bitcoin without having an emergency fund as you can actually fix it up after even after you have bought bitcoin, not having an emergency fund at first shouldn't be an excuse for not buying bitcoin.