All Fib levels match with support or resistance quite accurately on this chart.
The drop Ethereum can experience could be from neckline to 1.618 level on the condition we break the 400 support, which is a key level.
I am using a pattern in conjunction with Fibonacci levels, because if we use the pattern in a straightforward way we get Ethereum below 0.
If support holds convincingly a rally to 636 can happen. I find that unlikely though, but possible. It would depend how Ethereum performs at the 400 level.