Eric Falkenstein makes a great case on high frequency trading

here, making similar points that I did last week. But he also articulates something that I only mentioned in subsequent comments on other sites, namely that the 'front running' of 'flash orders' pales in moral comparison to the shenanigans of the 'good ol' days':

An algorithm chasing micropennies does not instigate trends the way portfolio insurance did in the 1987 crash, because in that case long-only funds were looking at their total long position, selling into declines (emulating a put option). The current algorithms generally look at relative value trades between sectors or issues, momentary order imbalances, a very different beast. Trade imbalances have always and will continue to move prices, but that isn't the computers fault. If there's continually 10x as many sell orders as buy orders, the result is going to be lower prices no matter what market is created. When buys and sells are coming in with equal size, price stability will be restored. To suggest the computers could exaggerate a movement is hysterical fear mongering in this context, because while anything is possible, it's a baseless hypothetical. Maybe we should regulate financial textbook writers as they popularize models that create things like CDO's that were so prominent in our latest financial crisis? Perhaps he is diverting our attention from his crime of the century?