Your link should work but all I get is io9’s front page. And I get stack overflow errors all over the place. I found the article after a while, though.
Anyway, here’s the underlying idea. Stock prices change from moment to moment. With modern technology they change faster than ever. But why do they change? Well, theory says that people with better information about the value of the stock take advantage of that knowledge by exploiting the price through higher or lower bids.
Again, theoretically, if you have a piece of information first you can exploit it best. First can literally mean milliseconds. If a stock is being asked at 1.65 and you think it’s worth 1.66 then by placing a bid of 1.66 first you can shut out the others. Those others may now bid 1.67 for it and you sell, making your penny profit times however many shares you bought. For 1,000,000 shares that’s $10,000. And the more times you can do that in a day, the more money you can make. If milliseconds count, then the fastest software and the fastest connections and the best location can make you more money than the slower pokes.
The article also talks about prices being different in different markets and making money off buying at the cheap price and selling at the high prices. That’s called arbitrage. It’s another way to value better information. Prices will tend to reach an equilibrium but the first ones in can make money.
Personally, I don’t see this as anything much more than a technical variation of what day-trading was during the stock boom. It sounds all futuristic, but the principal of having better information sooner goes back to the days of fast ships and carrier pigeons. Telegraph systems started in several countries at the behest of traders, and even where they didn’t start them they soon became the biggest users. The exploitation of arbitrage is also a classic technique of the math gurus. Today everybody looks to exploit the same set of differences, which dampens the amount that can be made. Speed is still helpful but there’s less value there to exploit.
The down side of this is that while you can make money faster, you can also lose money faster. Your information has to be correct and your interpretation of that information has to be correct. Day-traders got killed by bets that the market would keep going up. The expenses inherent in multiple trades don’t go away by speed. If you can buy a stock and have it appreciate 10% over a year with one purchase and sale commission expense, then you’re far ahead of someone who got a 10% return with a thousand purchase and sale expenses. You’d have to consistently return, say, 20% to make up for those expenses. And nobody has ever done that without cheating.
That’s why all this is so controversial. Perfect information is self-canceling. There are no differentials to exploit. The same advances that allow for speedier exploitation are also used to spread the knowledge everywhere equally. If the value of the advantages has to be more than the cost of the expenses then there are fewer ways to make money.
It’s a fascinating field to read about because it’s a real world example of the value of pure information. I wouldn’t get anywhere near it with my money, though.