http://custom.forbes.com/2017/02/02/lightspeed-trading/
Volatile markets can make or break a trader’s month, year — or even career. We only have to look back as recently as June 2016 following the Brexit vote. Market volatility around the world spiked. Many brokers’ systems couldn’t keep up with the speed at which markets were moving. Trades weren’t executed; quotes ran well behind real time.