All case studies
IntermediateRisk ManagementKnight CapitalAlgorithmBug2012HFTRisk Management
Knight Capital: $440 million lost in 45 minutes due to a code bug
How a software deployment error led the third-largest US market maker to near-bankruptcy in less than an hour
M
MarketPedia Editorial
9 min read·August 1, 2024
On August 1, 2012, Knight Capital Group lost $440 million in 45 minutes due to an old algorithm that was accidentally reactivated. The company was forced to seek a buyer within days.
Knight Capital: the third largest US market maker
Knight Capital Group handled approximately 10-15% of all daily trading volume on the NYSE.
45 minutes of rogue trading
Between 9:30 AM and 10:15 AM, an old algorithm that had been accidentally reactivated executed unintended trades in 154 different stocks—buying when it should have been selling. The losses reached $440 million in just 45 minutes. Knight only had $365 million in capital.
Lessons
- Pre-deployment testing is non-negotiable.
- Legacy code is a time bomb: decommissioned algorithms must be purged.
- Kill switches must be functional: it took the team 45 minutes to realize there was a problem.
# Knight Capital# Algorithm# Bug# 2012# HFT# Risk Management