Twitter traffic can predict the Stock Market
"The question that Bollen and co ask is whether any of these states correlates with stock market prices. After all, they say, it is not entirely beyond credence that the rise and fall of stock market prices is influenced by the public mood.
So these guys took 9.7 million tweets posted by 2.7 million tweeters between March and December 2008 and looked for correlations between the GPOMS indices and whether Dow Jones Industrial Average rose of fell each day.
Their extraordinary conclusion is that there really is a correlation between the Dow Jones Industrial Average and one of the GPOMS indices--calmness."
Link to the paper: http://arxiv.org/pdf/1010.3003v1?