[Image taken from here]
According to this article, the global money supply is estimated to be around $90 Trillion.
Here is a rationale that you may want to consider: what is your current net worth, in $?
If you would like to conserve this net worth in a world where Bitcoin holds the majority of the value, one might argue that you should simply hold the same proportion of the global money supply as you do right now.
For example, let's assume your net worth is $90,000.
This means you control 90,000 / 90,000,000,000,000 = 0.0000001% of the world's money, about one billionth of the global money supply.
One billionth of Bitcoin supply is 0.021 BTC, which at the time of writing (Aug 9th, 2019) costs roughly $250.
That seems like a very reasonable price for your "Bitcoin insurance policy".
Note: this is not investment advice. These are merely my thoughts and reasoning, you may want to consider them, and if you find them useful, I am glad to have helped you.
EDIT: Cool, this was retweeted by Davincij15! :)
(Originally appeared on Uptrennd)