Liquidity Bridge Glossary

Middleware that connects trading platforms (such as MetaTrader 4 and MetaTrader 5) to liquidity providers, enabling price streaming, order routing, and trade execution. A bridge translates between different protocols (FIX, TCP, WebSocket) so brokers can aggregate prices from multiple LPs and distribute them to their platforms.

A Liquidity Provider (LP) that supplies market data and pricing to the bridge. Makers connect via FIX API and stream bid/ask quotes for configured symbols. In XiroLink, each Maker connection is configured independently with its own host, port, comp IDs, and heartbeat settings.

A trading platform or system that consumes aggregated and marked-up prices from the bridge. Takers connect via TCP, WebSocket, or FIX protocol. Examples include MetaTrader 4, MetaTrader 5, cTrader, or proprietary trading platforms. Each Taker has its own connection, symbol mapping, and markup profile.

Financial Information eXchange protocol — the industry-standard messaging protocol for electronic trading communication. FIX enables real-time exchange of trading information between financial institutions, including market data, order entry, and execution reports. It is the primary protocol used by liquidity providers for price streaming.

A specific version of the FIX protocol widely used in the forex and CFD industry for LP connectivity. FIX 4.4 supports market data requests, security definitions, and order management. XiroLink uses FIX 4.4 for all Maker (LP) connections, handling session management, sequence numbering, and heartbeat monitoring automatically.

The process of combining prices from multiple liquidity providers for the same instrument to create a composite feed with the best available bid and ask prices. When multiple Makers provide the same symbol, the bridge selects the best bid (highest) and best ask (lowest) to create optimal pricing for Takers.

The process of translating instrument names between different systems. Different liquidity providers and trading platforms often use different naming conventions for the same instrument (e.g., "EUR/USD" vs "EURUSD" vs "EURUSDm"). Symbol mapping ensures that prices from any source reach the correct destination regardless of naming differences.

The normalized, internal instrument identifier used by the bridge to connect Maker symbols to Taker symbols. In XiroLink's 3-layer mapping system, Maker symbols are first mapped to Universal symbols (e.g., LP sends "EUR/USD" which maps to Universal "EURUSD"), and then Universal symbols map to each Taker's naming convention.

A named set of per-symbol spread markup rules that can be assigned to one or more Takers. Markup profiles allow different trading platforms to receive different pricing from the same LP feed. For example, a "Standard" profile might add 1.0 pip markup to EURUSD, while a "VIP" profile adds only 0.3 pips.

The additional spread (in pips or points) added to the raw LP prices before distributing them to a Taker. Spread markup is the primary revenue mechanism for brokers using a bridge. It is applied symmetrically to both bid and ask prices and configured per symbol within a markup profile.

The ability to add, modify, or remove bridge configuration (Makers, Takers, symbol maps, markup profiles) without restarting the bridge engine. Hot configuration ensures zero downtime during operational changes — individual connections can also be restarted independently without affecting others.

A fixed-size, circular data structure used by the bridge for high-performance message queuing between Maker price ingestion and Taker price distribution. Ring buffers provide constant-time read/write operations with predictable memory usage, ensuring the bridge maintains consistent throughput even during high-volume market conditions.

Transmission Control Protocol — a reliable, connection-oriented network protocol used for Taker connectivity. TCP ensures ordered, error-checked delivery of price data from the bridge to trading platforms. It is one of the three Taker protocols supported by XiroLink, commonly used for MetaTrader connectivity.

A full-duplex communication protocol over a single TCP connection, used for real-time Taker connectivity. WebSocket provides lower overhead than traditional HTTP polling and is ideal for streaming price data to web-based trading platforms or custom front-ends. Each Taker using WebSocket gets its own dedicated listen port.

Electronic Communication Network — an execution model where client orders are matched directly with liquidity from multiple providers. ECN brokers use liquidity bridges to aggregate prices from multiple LPs, creating a genuine composite feed where the best bid/ask from all providers is presented to clients.

Straight-Through Processing — an execution model where client orders are passed directly to liquidity providers without dealer intervention. STP brokers use bridges to route orders to LPs with optional spread markup, ensuring transparent and fast execution from the client through to the LP.

A financial institution or entity that supplies bid and ask prices for tradable instruments. In the bridge context, LPs connect as Makers via FIX protocol and stream real-time pricing. Examples include banks, prime brokers, non-bank market makers, and aggregators like LMAX, Currenex, and Integral.

An execution model where the broker passes all client trades directly to liquidity providers via the bridge. In A-Book execution, the broker earns revenue solely from the spread markup applied in the bridge, with no market risk from client positions. The bridge handles the routing from client platform to LP.

An execution model where the broker internalizes client trades, taking the opposite side of the trade rather than routing it to an LP. In B-Book execution, the bridge may still aggregate LP prices for reference pricing and display, but the broker bears the market risk of client positions.

Software that sits between liquidity providers and trading platforms, handling protocol translation, price aggregation, symbol mapping, markup, and distribution. A bridge middleware like XiroLink abstracts the complexity of multi-LP connectivity so brokers can manage their liquidity infrastructure through a unified dashboard.

Short for "Computer ID" — a unique identifier used in FIX protocol to identify the sender and target of messages. Each FIX connection requires a SenderCompID (identifying the bridge) and a TargetCompID (identifying the LP). These are assigned by the liquidity provider during the onboarding process.

The time interval (in seconds) at which FIX protocol heartbeat messages are exchanged between the bridge and the liquidity provider. Heartbeats ensure the connection is alive — if no heartbeat or other message is received within the expected interval, the bridge triggers reconnection logic to restore connectivity.

The automatic switching from a primary liquidity provider to a backup when the primary becomes unavailable. In symbol mapping, failover is configured by assigning primary and fallback Makers to each Universal symbol — if the primary Maker disconnects, the bridge seamlessly switches to the fallback provider.

The optimal prices derived from aggregating quotes across multiple liquidity providers. The best bid is the highest buy price available, and the best ask is the lowest sell price available. Multi-LP aggregation produces best bid/ask pricing that is tighter than any single provider, benefiting the broker's clients with better execution.