
So when NASDAQ generates a stock market ticker signal indicating that IBM is now trading at $160/share, your order into NASDAQ could be as quick as 250 nanoseconds plus the time it takes your algorithm to decide to buy. The 250 nanoseconds are how much time it will take for the market data, a UDP network packet, to be brought into the FPGA-based NIC, plus the time it will take to generate the order as a TCP packet and inject that order back into the exchange. To put this into perspective, 250 nanoseconds is the time required for a photon of light travel 82 yards, less than a football field.
If that doesn’t sound fast enough, this week Solarflare, LDA Technology, and Xilinx announced LightSpeed TCP which under the proper circumstances can reduce network latency for trades from 250 nanoseconds down to 120 nanoseconds. So by contrast, 120 nanoseconds are the time required for light to travel 40 yards. So they’ve taken trading from a kickoff return to a few first downs.
