The difference between display data and executable prices
Many trading interfaces show a price that updates in real time but is not the price at which your order will actually execute. The displayed price is often derived from a data feed that trails the executable market by a fraction of a second — which, in fast-moving markets, can mean a materially different fill price than the one you saw when you decided to trade. Ask the operator explicitly whether the price displayed in the interface is the price at which a market order will be filled, or whether execution happens at a different price determined at the moment the order reaches their system.
Level 1 versus Level 2 data — and why the distinction matters
Level 1 data shows the current best bid and ask price for an instrument. Level 2 data shows the full order book — the prices and sizes of multiple bids and asks stacked behind the best price. For retail traders in liquid markets, Level 1 data is often sufficient. For traders using size, or operating in less liquid instruments, the absence of Level 2 data means you cannot see the depth of the market and may misjudge slippage on a larger order. Confirm which level of data your account tier provides before you trade at size.
Latency and its practical effect on retail traders
Latency — the delay between a price change in the underlying market and its appearance in your trading interface — is measured in milliseconds for professional traders but can be several seconds for retail interfaces that update through web-browser connections rather than direct exchange feeds. For most retail traders using end-of-day or swing strategies, this latency is irrelevant. For traders who make decisions based on real-time price action, the latency of your data feed is a material variable that should be disclosed by the operator and confirmed before you commit to any strategy that depends on real-time precision.
How to evaluate data feed quality before committing
Request a demo or paper-trading account before funding a live account. During the demo period, compare the prices shown in the interface against prices from a separate, independent market data source such as a financial data terminal or a publicly accessible exchange feed. Note the consistency of the spread and the speed of price updates during periods of higher market activity. This direct observation gives you more reliable information about data feed quality than any written specification in a marketing document.