At the core of the digital world sits a new generation of electronic gatekeepers: a mixture of highly sophisticated computer algorithms tended and programmed by a small cadre of elite technocrats who determine what we see in the online world. In 2010 the stock exchange suffered a ‘flash crash’ when shares fell by 6 percent in 5 minutes. The crash was caused by trading algorithms. Trading algorithms are now so sophisticated they can feed on each other’s intentions and try to trick each other into making buys or sells favorable to the companies that unleashed the algorithms in the first place. Some trading algorithms, for example, can detect the electronic signature of what is called a V-WRAP (Volume-Weighted Average Price.) This important because V-WRAP’s are a trading benchmark used especially in pension plans, so they are relevant to the overwhelming majority of people. The detecting of the electronic signature is nicknamed ‘algo-sniffing’ and can earn its owner substantial sums: if the V-WAP is programmed to buy particular shares, the algo-sniffing program will buy those shares faster than the V-WAP, then sell them to it at a profit. Whatever the ethics, algo-sniffing is legal. Some trading algorithms are specifically designed to fool other trading algorithms. This process is called ‘spoofing.’ A spoofer might buy a block of shares and then issue a large number of purchase orders for the same shares at prices just fractions below the current market price. Human traders would then see far more orders to buy the shares in question than orders to sell them and likely to conclude that their price was going to rise. They might then buy the shares themselves, causing the price to rise. When it did so, the spoofer would cancel its buy orders and sell the shares it held at a profit. It’s very hard to determine just how much of this kind of thing goes on, but it certainly happens. In October 2008, for example, the London Stock Exchange imposed a £35,000 penalty on a firm (its name has not been disclosed) for spoofing.
Sniffing and Spoofing
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