Pacer Adopts Bloomberg AIM, EMSX and RBLD for ETF Rebalances

Pacer Advisors has implemented Bloomberg’s Asset and Investment Manager (AIM) and EMSX execution system together with the Rule Builder (RBLD) Optimizer to automate ETF rebalances and broker allocation workflows.

The integration links AIM’s order management and PM<GO> portfolio tools with EMSX and RBLD so portfolio managers can compare portfolios against benchmarks and targets, generate orders and send them for optimized execution. Pacer said the setup replaces manual spreadsheets and one-off allocation processes used during rebalances.

Pacer’s deployment uses the RBLD Optimizer to evaluate entire baskets at once rather than allocating one order at a time. Bloomberg says the optimizer can apply multiple constraints at the same time, including share distribution, dollar imbalances, broker commissions, pre-allocations, liquidity footprint and order cost. Orders are grouped into coordinated batches and released to brokers from within EMSX, a process Bloomberg says shortens work that previously took traders hours.

The combined AIM–EMSX–RBLD workflow creates dollar-neutral, proportionally balanced baskets intended to reduce overnight risk and cash drag while enabling brokers to execute more efficiently. Pacer expects fewer manual calculations, improved allocation accuracy and scalable execution capacity for high-volume ETF portfolios.

“Bloomberg’s RBLD Optimizer has transformed how we approach rebalance execution,” Danke Wang, Head Portfolio Manager at Pacer Advisors, said. She added the firm now focuses more on execution and less on setup during each ETF rebalance.

Bloomberg describes Rule Builder as a multi-asset automation tool that supports fixed income, FX and equities trading across its execution venues and dedicated apps, including TSOX for fixed income, EMSX for equities and exchange-traded derivatives, and FXEM for FX. Ravi Sawhney, Head of Product for Buyside Execution at Bloomberg, described the integration as bringing advanced optimization directly into the execution workflow to help clients solve multi-constraint allocation challenges more quickly and efficiently.