Do you know how much money disappeared overnight because of this?

I do know, none. Not a single cent disappeared. Because stocks aren't liquidity. That money was never there in the first place. Some paid some money to get those stocks, that money was real and it entered the company's liquidity. Then they spent it on something. Those stocks are but the promise of paying some dividends, some time in the future or giving some power inside the company. Their virtual fluctuations of price over time are nothing but smoke and mirrors, people exchanging virtual titles over those rights like little kids trading collectible cards. Some people cashed out for a low price (that was already grossly overinflated from the pandemic days, so they probably still made bank) and it pushed an already correcting stock to accelerate for today. That money didn't come from the company, it was exchanged entirely by third parties, public traders. Ubisoft didn't participate at all in whatever pushed the price drop. No matter how much I want it to, Ubisoft is not in any more danger today than it was in yesterday. They are still filthy rich, if anything the biggest danger for this is that it gives them lee way to layoff another group of underpaid developers or gut another studio to appease the stockholders. Who are already in a frenzy for blood because Outlaws didn't make all the money.

If you were to compare Ubisoft today to Ubisoft 2 years ago, you would see they dropped nearly 93%. Dear golly, how is this poor boutique family company in business after such a massive loss? /s