This is the VOA Special English Economics Report.

Once, stocks were traded through the open outcry system, with men shouting share prices on the floors of stock exchanges.

But the sights and sounds of stock traders furiously exchanging securities has mostly disappeared. They have been replaced by fast, interconnected computers.

Joe Saluzzi is a head of equity trading at Themis Trading in New Jersey.

JOE SALUZZI: "The equity market has changed. It's no longer what you see on TV, it's no longer guys with colored jackets running around the floor anymore. That's the show, that's the TV studio. The equity market is a bunch of co-located computers strung together by a bunch of wires, everyone trying to race to zero. The speed of light is the goal — the speed of light!

That's what we're looking at now.