We often get too pragmatic while investing, and don't plan for the future at all. Proper planning is essential to make an investment successful. Even that plan should be from the beginning to the end of the investment. Every investor should consider having a back-up fund and it is better if this back-up fund is more than the amount invested. Because you can divide this back up fund into several parts and prepare different funds for different periods. Be it a reserve fund or an emergency fund, you prepare the funds depending on your needs. But I consider the emergency fund a must. An investor should always be prepared for the unexpected.
The reserved funds don't necessarily need to be bigger than the money invested. Provided you have as source of funds. In most cases, you don't even necessarily need to have the reserved funds set up in place before starting to invest in bitcoin. It is something you can gradually build up even after you made your investment. The most important thing is for you to get started with your investment. Waiting to build up a backup funds or reserved funds before starting your investment is not a wise practice.