It also sounds like the term front running refers to many different practices, this is from the Wikipedia article:
> One common practice of high-frequency traders (HFT) is a form of front running, where they peer into various exchanges and try to detect orders as they propagate from a broker's order router.
> HFT traders place many small orders that indicate buying/selling pressure. Those with the shortest lag in reaching other exchanges then place orders on those exchanges to catch the rest of the order, at a more advantageous price.[6] According to Harvard Political Review writer Austin Tymins, HFT hedge fund Citadel LLC made billions of dollars front-running the trades of large institutional investors, many of which are investing on behalf of middle-class clients.[7]
http://www.amazon.com/Flash-Boys-Insiders-Perspective-High-F...