I don't recommend using emergency fund for your bitcoin investing, the reason is because emergency can take place at any moment, and even if your income is coming weekly or monthly without missing, it is still a high risk to invest in Bitcoin with your emergency fund. If you desire to invest in bitcoin, seperate your investment fund from your emergency fund. This idea of using emergency fund for investment has caused troubles for some people who tried such a thing. Just take for instance, their is an emergency, maybe health challenge that requires taking someone to the hospital, if you have used your emergency fund for investment, such health challenge can endanger the persons life, but if the emergency fund is available you can easily handle that situation properly without facing financial problem.
Anyone who truly understand how Bitcoin investment works will never think of investing from his or her emergency funds, the reason why most people invest from Thier emergency funds is due to ignorant. Because if not ignorant there's no way an investor will think of investing from his emergency funds knowing fully well that there emergency funds is supposed to serve for other purpose, from the mention of the name
"emergency " we are supposed to understand that it is for emergency needs, while our discretionary funds is for our Bitcoin investment.