Haha, i still remember getting the message by Interactive Brokers FFH -10% and then saw the news about the short report, not gonna lie, it made me quite uneasy BUT there are undeniable fundamentals even if book value has some distortions (obviously the distortions pointed out by MW were misleading). BUT on first glance it induced some stress, especially considering it was 72 pages and a lot of mumbo jumbo too.
Then on top came the change in margin requirements for FFH positions by IB so yeah, MW hoped there is some panic selling which created a -12% drop.
I hope for him he sold immediately after that.