No. 008 · The Enter Key Gallery

45 Minutes, $440 Million

· 45 minutes

  1. 1New trading code reuses a flag that once enabled retired logic
  2. 2Deployment misses one of eight servers
  3. 3Market opens; that server runs the dead code
  4. 4It fires millions of unintended orders
  5. 5The firm loses about $440 million and needs a rescue ✕

Delete dead code. Verify every deploy target. Never recycle a flag.

Source: SEC order, October 2013

Knight Capital trading loss, August 2012. Duration: 45 minutes. 5 hops from the first change to the failure.