Hey there. Crypto allocations are dependent on the investor. Initially, my crypto position was only around 4%. It grew to nearly 10%, I trimmed back to 5%, and it has grown yet again back up to nearly 7%.
I know some people who have large exposure to crypto, often in excess of 20-30%, and I know some investors who hold 2%. Depending on your overall tolerance for risk, this will determine your position sizing. It could be 0%, 2%, 10%, 20%. It all depends.
For crypto, I would allocate the portion of your portfolio you are comfortable going to $0. This was my initial mentality when I bought. The mentality I took with the 4% position sizing I had was that if it went to $0, I still had 96% of my portfolio in tact and although it would be a loss that would sting, it wouldn't be a material one. And, if it went up with the potential like lots say there is, I would realize the benefits. I've booked more than the initial 4% I put in as profits already, so I am in effect investing on house money with Bitcoin at this point in time. If it ran up to 8-10% again, I would very likely trim.