Having a Bitcoin investment for 4 years is okay but you should start when the bear run comes. That will help you to buy Bitcoin at a lower price and keep buying using DCA methods. That also helps you to accumulate more Bitcoin than you started with at this time because the price has already increased. But if you want to start now, that will not be a problem.

Before you start, you need to allocate the funds to invest for 4 years or more. You can also split your income and prepare it for the investment. But you need discipline to invest in Bitcoin for 4 years or more because that will be a long journey and not many people will be able to do that.

Many of them will be bored buying Bitcoin for 4 years or more so it needs courage to keep focus with your plan. Let's say we try hard in our first 4 years and after that, we will see how bigger our profit in the investment. So we will know when the time limit is to sell our Bitcoin.