This paper examines spillover channels of fast trading technology to the equilibrium speed demand of speculators and speed supply by exchanges. As the speed technology of speculators advances, more speculators rush to be fast and to trade faster in order to benefit from the first-mover advantages. This generates a negative externality of excessive speed investment and deteriorates profit for both fast and slow speculators. As the speed technology of exchanges advances, faster exchanges make fast speculators more concentrated and faster in equilibrium, reducing the fraction of ever-fast speculators. This fast and furious trading can increase the deadweight loss of speed investment and reduce price informativeness. Policy-makers aiming to improve price discovery and reduce costly speed investment may find a mismatch between their desired exchange speed and the equilibrium speed supplied by the exchange, echoing the concerns of market failure on speed arms races.