To protect yourself from losing money by investing in Bitcoin, first of all, the investor must gain proper knowledge about Bitcoin. Buy Bitcoin in the hope of making quick money without knowing anything increases the possibility of loss.
You're right. We need to have proper knowledge before we buy Bitcoin. Even if Bitcoin is quite safe, we may buy at expensive price if we have no understanding about Bitcoin. There are many people who buy at expensive price and they end up with selling for losses. People give up because the price keeps declining for a long time. Besides knowledge, mentality is also another important part here. People who have no strong mentality, they can give up easily and sell the Bitcoin for losses.
Another thing is that buy Bitcoin with prudent money is good. As a result, Bitcoin can be purchased continuously and Bitcoin can be held in the long term, thereby reducing investment risk.
Agree, we must invest in Bitcoin with safe money. We mostly hold Bitcoin for few years, we must be ready with any challenges during those years. If we use the money allocated for the main necessities, we may get difficulty if we need the money someday. No doubt that we will be always fear for losses if we choose this way. So, it is important to remember for using the money that we afford to lose.