Knight Capital: How One Forgotten Server Lost $440 Million in 45 Minutes

On August 1, 2012, Knight Capital suffered a loss exceeding $440 million within 45 minutes. The incident occurred when new code for a NYSE program was manually deployed to seven of eight servers. The eighth server retained retired 2003 code triggered by a reused feature flag. This caused the SMARS automated router to execute 4 million trades erroneously. The SEC documented the failure, highlighting critical lessons regarding manual deployment and the risks of reusing feature flags.