XMR will release bulletproofs soon, and we might see a temporary 'sell the news' downturn or perhaps stagnation. In contrast, ETH has already dipped over the past week, and we should expect it to regress to the mean, maybe even hitting $400. As a result, ETH may go up against XMR.
I might be wrong, you never know. Maybe Monero will keep going up, perhaps peaking at 0.64. But I wouldn't bet on it. I would rather sell part of the XMR I bought at $80 and hold ether for a while, rebuying Monero all the way down to 0.3 ETH.