German lawmakers stole a march on their European counterparts last month with the introduction of one of Europe’s first pieces of legislation designed specifically to curb high-frequency trading.

The rules came into force on May 15, though affected firms have between six and nine months to comply with its most onerous elements. That deadline has left German regulators and exchanges scrambling to get trading firms up to speed, fearing that uncertainty and the burden caused by the legislation could drain liquidity from the country's markets.