Flash crashes aren't an inherent part of HFT, they're generally caused by buggy software. Computer caused crashes have happened long before HFT became popular,

Flash crashes aren't an inherent part of HFT, they're generally caused by buggy software. Computer caused crashes have happened long before HFT became popular, and so for that matter have human caused crashes ("fat-finger crashes"). IMO. The main problem is that exchanges can't afford talented developers, they simply don't have the money to compete with the banks and hedge funds. Most exchanges have stop signals (i.e. a message they can broadcast that can stop computer trading, etc.) but often they fail to use them. Exchanges should be implementing algos to better detect abnormal behaviour (whether by human or computer) and prevent flash crashes before they happen.