See how fake tweet rocked stocks

See how fake tweet rocked stocks

How could a fake tweet about an attack on the White House trigger a stock market slide?

It happened just over one year ago on April 23, 2013.

Someone broke into the Associated Press' Twitter account and sent out a false headline about explosions at the White House. Almost immediately, the Dow plunged and then rebounded as it became clear there had been no attack.

Here's CNBC's Courtney Reagan with a "Heat Map Time-Lapse" look back at that day and the questions it raised about computers triggering trading programs.

- By CNBC staff