Same Pair, Same Second, Different Price: Anatomy of Broker Quote Gaps

[Shadow Trader]

Two brokers showing the same pair at the same moment rarely display identical prices. The difference starts with the source feed. Each broker draws from its own set of liquidity providers, and each provider's stream reflects its inventory, risk appetite, and view of short-term flow.

Next comes price construction. A broker may take the best bid and best offer from several providers, rely on a single provider, or blend streams into a composite. A markup is then applied, either as a visible commission or as extra spread built into the quote. Rounding and decimal precision also vary between platforms.

Timing adds a further layer. Feed latency, server location, and how often the platform pushes new ticks determine how current a displayed price is. A platform that sends fewer updates may show a stale price even though the underlying feed has already moved.

For scalpers, these differences matter most when a strategy depends on small edges. Comparing tick data from two brokers over the same session can reveal which one lags, which one widens at specific times, and whether backtests on one feed transfer cleanly to another.