Europe's most influential high-frequency trading firms including Getco, Citadel Securities, Knight Capital and IMC have warned European regulators that a “one size fits all” policy on computer-driven trading would harm the quality of the market and have called for greater flexibility over new trading rules.

Responding to a consultation paper on European guidelines for automated trading, the European Principal Traders Association, a lobby group representing 20 of Europe's largest proprietary trading firms, said: "Guidelines that impose unnecessarily burdensome compliance requirements on all firms would constitute a significant barrier to entry and competition for participants in electronic markets, and would thereby harm market quality."