S3 has connected to Bruce Markets’ US equity market-data feed, adding another overnight venue to the information used by its execution-analysis clients. Announced on 14 October, the integration gives brokers more evidence for reviewing prices and liquidity when much of the conventional trading day has ended.[1]
The addition builds on an existing service. S3’s product documentation already identifies Blue Ocean Technologies as a source of 24/5 data and describes extended-hours analysis using consistent execution metrics. Bringing Bruce into that process can widen the observed market against which a transaction is assessed.[2]
Bruce’s importance to that comparison is illustrated by its own market-share claim: more than one-fifth of reported overnight notional across three leading alternative trading systems in the fourth quarter to date, as reported on 14 October. That is an early-quarter share of a specified venue group, rather than a completed-quarter measure of all US equity trading.[1]
S3 says its analytics support exception reports, examination of individual trades and a record of reviews across teams. Its depth-aware analysis also considers available size. Those capabilities address an important distinction: a displayed price for a small quantity is not necessarily a realistic benchmark for executing a much larger order.[2]
For a broker, additional venue evidence can help separate an unusual execution from a market that was thin at that moment. The result still depends on the time, size and venues represented in the underlying data.[2]
The connection expands S3’s evidence for execution review; brokerage access to Bruce for trading remains a separate arrangement.[1]
Sources & further reading
- S3 connects to Bruce Markets’ US equities data feed Bruce Markets · 14 Oct 2026 · Accessed 21 Oct 2026
- Best Execution Analytics — extended-hours analysis and market data S3 · Accessed 21 Oct 2026