Felix Salmon
on high-frequency trading:
“We don’t understand the feedback loops between [computerized trading algorithms]. We don’t understand what causes individual stocks or entire market indices to move. We have an incredibly complex system with only the most rudimentary controls. And we got a hint of what could happen last May, during the flash crash, but we have no idea what other things might happen.
I’ve spent the better part of five years ghostwriting for people and companies involved in this kind of stuff. In many ways, computerized trading is similar to, well, any communications process that has a highly technological component: It’s sheer awesomeness does not make it perfect. A cell phone call, for instance, goes from an iPhone all the way up into bloody space, hits a satellite, and is redirected to another handset that’s anywhere from a block to fifty-thousand miles away. This happens in only a couple of milliseconds; it’s profound and amazing. But sometimes the signal gets lost — sometimes, the technology messes up — and the call drops.
The technology that powers the markets is like that — imperfect — too. It misbehaves, and when it makes a mistake there’s no unscrambling that proverbial egg. The vast majority of the time those mistakes are very benign and cost the trading desk insignificant sums of money, and no one outside that desk even hears about them. But instead of cutting off a call mid-sentence, the worst that can happen is global economic catastrophe that costs a literally incalculable sum of money to market participants.