Worst one-day drop you've ever suffered?

While witnessing the carnage in SAAS, fin-tech, high beta, or any of the popular picks on this sub (looking at you, PayPal), I tried to look up some of the largest one-day drops of big companies in recent years. When you Google it, the only things that come up are lists that sort by market cap lost in one day, so it's basically just Nvidia and Meta. I'm interesting in YOUR largest single day drop you've experienced in a stock you've owned. Try not to list some obscure mining company in Peru or a biotech microcap, as a 50% drop on bad news is basically par for the course. I'll start: I've owned Fortinet (FTNT) since 2021. I still happily hold, and actually added some shares recently. It's a fantastic business, but the stock can be really volatile for how stable the earnings tend to be. On two separate occasions, I've woken up to drops after earnings that bottomed around -30% intraday at the lows. Neither time had anything disastrous, just one or two disappointing numbers for the guide. I intend to stay a shareholder into the 2030's, so it just served as a nice buying point, but my portfolio was definitely BLEEDING that day. Interested in your largest drops, include a brief explanation if you can. I have a feeling the Fiserv guys might wanna sit this one out for PTSD reasons...