When Twitter Rogues Move Markets: A Timeline - Businessweek
Eric Barker stashed this in Tech
Stashed in: Twitter!
"On April 23, a tweet sent from the official Associated Press Twitter account reporting that an explosion at the White House had injured President Obama caused the Dow to drop 140 points and wiped $136 billion from the S&P 500. The incident came shortly after the U.S. Securities and Exchange Commission announced that companies can use social-media sites such as Twitter and Facebook to share market-moving company announcements."
It's official: never buy or sell based solely on what you hear on Facebook and Twitter.