I knew this was possible: """
One very popular variety of high-frequency trader is the statistical
arbitrageur, or "stat arb." Stat arbs make their money by vacuuming up
mountains of historical data and looking for correlations between
various datapoints and asset prices. The stat arb's trading platform,
which is basically a large computer system manned by programmers and
financial engineers, uses those correlations to build predictive
models that take in a stream of information inputs like news reports
and stock prices (Thompson Reuters sells a service that fires wire
reports at very low latency to these systems), and output a rapid-fire
stream of "buy" and "sell" orders for different assets. For instance, a stat arb HFT platform might identify a direct
correlation between positive news about Steve Jobs' health and
increases in the price of AAPL; then the microsecond that the platform
receives and processes an in-bound Reuters news packet containing a
statement about Jobs' cancer-free status, it would immediately spit
out a "buy" order for AAPL on the expectation that Apple stock is
about to increase in price once this news becomes more widely known.
""" -- from http://arstechnica.com/tech-policy/news/2009/07/-it-sounds-like-something.ars/2


