Latency is rapidly approaching the physical limits of the universe set by quantum mechanics and relativity. But perhaps not even Einstein fully appreciated the degree to which electromagnetic waves bend in the presence of money. Kevin McPartland of the Tabb Group, which compiles information on the financial industry, projected that companies would spend $2.2 billion in 2010 on trading infrastructure—the high-speed servers that process trades and the fiber-optic cables that link them in a globe-spanning network—all just to cut a few hundredths of a second off the time it takes to receive data or send an order.
Wired dives into high-frequency trading.