The upgrade is designed to support the needs of ultra-low latency and IOC customers and includes matching engine optimization and connectivity advancements. The firm is currently in the process of transitioning customers onto the new FIX architecture.

"Millennium is known for its pioneering role in dark pool execution, diverse liquidity and high execution quality," said Brian Carr managing director and co-head of Sell-Side Services at ConvergEx Execution Solutions. "This upgrade continues Millennium's long established tradition of excellence and keeps customers at the forefront of execution technology."

Millennium is one of the industry's most comprehensive continuous ATSs in the U.S. equity market, aggregating more than five billion shares of available liquidity in over 6,000 symbols daily. Over 100 broker-dealers access the Millennium ATS every day.

ConvergEx operates two ATSs, Millennium and VortEx®. The firm offers customers anonymous access to diverse and deep order flow, including tools to seamlessly access liquidity in both Millennium and VortEx simultaneously. These advanced proprietary technologies seek to improve overall execution quality by helping to reduce information leakage, market impact and execution expenses.