Stock prices already tanked. That's the point.
40% of CDPR's shares are held by management. 60% are free float. Among that 60% are 191 institutional shareholders. Institutional shareholders aren't fans -- they're market performance maximizers. If they feel that their net loss can be best mitigated by participating in a lawsuit, then that's what they will do. Right now that's a big "if", that many of them will be actively assessing. No way of knowing which way they'll go, but a suit is not improbable. Keep in mind that there are also ADR / ADS shares to deal with under U.S. securities jurisdiction.
They haven't exactly tanked. They dropped over 40% yes, but they haven't hit their low point yet (which was just over 14 usd). Not good in any case, but they've shown the ability to improve their stocks before, so as a potential investor I have to ask will they do it again, and now if I think they can, is the time to buy, before the expansions are announced and other investors start buying into it.
Yet right now they're not buying either, or at least their buying/selling is staying at about even pace. But they're no longer jumping ship either.
So if I'm a long term investor, or I'm a billionaire managemer in CDPR, this may not be a bad thing, maybe this is the time to buy.
But here's an interesting thing to look at. Like you said the 40% of the shares are owned by management, 60% are free float. Stock prices have dropped just over 40%. Assuming that management isn't selling their stocks, that kind of means that most of their free float stocks are back on the market, except for about the same percentage of stocks that are institutional shareholders. Now why would institutional shareholders hold onto stocks on a sinking ship. They wouldn't.
So either they've already bailed, and it's just long term hopefuls that are holding onto their free float stocks, or they see something we don't.