Edit: Found it. https://rhsfinancial.com/2017/06/line-aggressive-crazy/
I hope you really think about applying the Kelly Criterion to trading bitcoin futures and hope you realize that the person completely ignores friction(transaction costs),and does not show a sharpe ratio( who cares if you beat a benchmark with 10x the risk).
"[In November 2000.] Those kinds of times… when everyone is running around like a chicken with its head cut off, that's pretty good for us… "~Jim Simons (https://en.wikipedia.org/wiki/Renaissance_Technologies)
If you're able to associate some timeframe to the idea that with p = 1 Bitcoin will be at half the value it currently is, the Kelly criterion suggests you should be quite a bit of the farm. Applying the Kelly criterion in supposed p = 1 situations (e.g. "Like it or not, [the market will crash]") is pretty invalid.
Even if bitcoin is certain to crash, without a deep understanding of when (and by extension, how) a naive futures trader still runs a good chance of being eaten alive, or making poor returns.
Stating bitcoin will crash is a bit like the conventional wisdom that smoking is bad for your health. One can reasonably be very confident in the truth of it without being confident in specific odds on any bad outcome.