Order and execution management is the layer that turns an intent to trade into filled orders: an OMS holds the order lifecycle and books-and-records, an EMS gives traders the tools to work that order in the market, FIX carries the messages between counterparties, and a smart order router decides which venue each slice goes to. Most firms run all four; the question is whether they run as one system or four integrations.
This hub collects the guides that explain each layer in plain terms — what it does, where firms usually break it, and what to test before you buy — plus the Gato modules that handle order flow, connectivity, and execution.
6 in-depth guides covering the rules, the systems, and the trade-offs.
The platform components built for the workflows in this topic.
An OMS owns the order record: allocations, compliance checks, books-and-records, and the audit trail. An EMS owns the execution: routing choices, algo parameters, market data, and the trader's blotter. A single platform can serve both roles, and increasingly does, but the responsibilities remain distinct.
Direct market access sends your order to a venue you choose. Smart order routing chooses the venue for you, slice by slice, based on price, size, and fill probability. Firms trading a single venue may not need SOR; anyone trading fragmented markets with best-execution obligations generally does.
Inline, on the order path, before the message leaves for the venue. SEC Rule 15c3-5 requires controls that cannot be bypassed, which rules out post-trade-only surveillance or checks that sit beside the routing path rather than inside it.
Run the failure cases, not the demo: a venue session dropping mid-order, a sequence-number gap on reconnect, a partial fill followed by a cancel-replace, an order rejected by a pre-trade limit, and a busted trade. Ask to see the audit trail each scenario produces, and confirm the same record is what feeds CAT reporting rather than a separate export.
Fewer than most firms end up with. Each destination technically needs a session, but a connectivity hub can maintain those sessions centrally and present one normalised interface to internal systems, so adding a venue does not mean another integration for the OMS, risk, and reporting layers to absorb.
