I genuinely think a Great Depression sized 90% reduction is plausible. If the Trump administration somehow makes a trusted ironclad commitment that they will never ever reduce the tariffs, but doesn't actually convince anyone that the tariffs are good, the market will still expect Congress or the next administration to reduce them. And thus capital investments will still be largely impossible in any sector exposed to them. (Even if your investment isn't directly exposed, can you be confident that Trump won't blow it up on some other quixotic crusade?)