I disagree somewhat. The ER report Weds. will probably not be a market mover, unless management comments on any M&A.
Z's FDA decision will probably be the market mover in late May, but it's still a win-win in my opinion. If Z's approved with baggage, RLYP wins. If Z gets an approval clean, RLYP is still the first mover, and the market is big enough for two players, focused on two different parts of the puzzle. And any potential acquirer is waiting for the Z FDA decision, to determine the premium for the take out. So I don't see a month long of volatility as you suggest, but rather one catalyst event at the end of May.