How a phony tweet and computer trades sank stocks

For a few surreal minutes, a mere 12 words on Twitter caused the world's mightiest stock market to tremble.

No sooner did hackers send a false Associated Press tweet reporting explosions at the White House on Tuesday than investors started dumping stocks eventually unloading $134 billion worth. Turns out, some investors are not only gullible, they're impossibly fast stock traders.

Except most of the investors weren't human. They were computers, selling on autopilot beyond the control of humans, like a scene from a sci-fi horror film.

"Before you could blink, it was over," said Joe Saluzzi, co-founder of Themis Trading and an outspoken critic of high-speed computerized trading. "With people, you wouldn't have this type of reaction." Continue reading "How a phony tweet and computer trades sank stocks"