Yesterday someone hacked the Associated Press twitter account and sent a tweet saying that there had been explosions in the White House and that the President was injured. The Dow Jones dropped significantly before returning to previous levels when it was discovered the tweet was a fake.
This highlights two very interesting things:
1. The power of instantanous news and social media on the stock market - even if the news is not true
2. Given that there has been a huge growth in High Frequency Trading - where shares are traded in milliseconds - someone could have made a lot of money doing this (I think).
Wall Street Journal has more on.wsj.com/11O38wx
Image from Factset via WSJ.