Just read about the NYSE getting slapped with a $9 million fine from the SEC over that whole 2023 trading mess they had. So basically in January 2023 they accidentally ran their primary and backup systems at the same time, which somehow made the system think opening auctions were already done for over 2,800 stocks. Like... they didn't even notice for almost 90 minutes? That's wild. Ended up causing this whole cascade of issues - trading halts, canceled orders, the whole thing. What got me is that NYSE apparently didn't have proper procedures to actually check if the opening auctions were happening. No monitoring system. The SEC found they violated their own rules, so they had to agree to stop doing it (obviously) plus pay the penalty. It's one of those situations where you realize how much infrastructure stuff matters behind the scenes. Not the flashiest story but definitely shows why exchanges need their systems locked down tight.