Price feed

What is a price feed

A price feed is the continuous stream of quotes (bid and ask prices) that a data source or broker sends to a trading platform, which the platform then displays and uses to execute orders.

Each new quote in the stream is called a tick. The bid is the price at which you can sell. The ask is the price at which you can buy. The gap between them is the spread.

A worked example

This is a hypothetical case. You watch EUR/USD in a platform's Market Watch window.

• A tick arrives. The bid and ask both move up slightly, and the spread stays the same.
• Another tick arrives a moment later. The bid stays put, but the ask moves up, so the spread widens.
• A news release hits. Several ticks arrive in quick succession, and the price jumps past levels that were never quoted in between.

If you had a market order to buy during that jump, it would fill at the next available ask in the feed rather than at the price you last saw. That difference is slippage. To see what such price moves mean in money for your position size, use the tools on the calculators page.

Where you see the term

• Platforms. In MT4 and MT5, the feed drives the Market Watch window, the tick chart and the candles on every chart. Each broker's server supplies its own feed, which is why the same instrument can show slightly different prices on different brokers.
• Reports. Trade confirmations and account statements record the price taken from the feed at the moment of execution.
• News and data services. Financial websites show a "live price feed" or ticker. These are often indicative quotes, meaning they are shown for information and may not be prices you can trade at.

Formal definition and edge cases

More precisely, a price feed is a time-ordered sequence of bid/ask quotes for an instrument from a specific source. Some feeds also carry depth (volume available at each price), last-trade prices for exchange-traded products, and timestamps.

Edge cases that experienced traders should know:

• Executable vs indicative. A broker's feed is usually executable for its own clients. A public ticker is often indicative only.
• Aggregated feeds. A forex price feed from a broker is usually built from quotes from several liquidity providers. The broker may add a markup to the spread. See dealer and A-book and B-book.
• Gaps and freezes. Around market open, during low liquidity or in a flash crash, the feed can skip prices, pause or show unusually wide spreads. Stop orders can then fill far from their set level.
• Price spikes. A bad tick (an erroneous quote) can trigger orders before it is corrected.
• Latency. The quote reaches you a moment after it was created. Fast markets make that delay matter more.
• Programmatic access. Traders who pull a feed into their own software do so through an API. See API trading.

Leveraged CFD and forex trading can lose money fast, and gaps in the feed can make losses larger than a stop-loss suggests. Read risk management before trading.

Related terms

• Big figure
• Fiber (EUR/USD)
• Fill and partial fill
• Counterparty
• Average daily range
• Circuit breaker
• Currency pairs
• Trading glossary

Frequent questions

What is a price feed in simple words?

It is the live stream of buy and sell prices that your trading platform shows and uses to fill your orders.

Why do two brokers show different prices for the same pair?

Each broker builds its own feed from its own liquidity sources and may add its own markup, so the quotes can differ slightly.

Is a live price feed on a news site tradable?

Usually not. Such feeds are often indicative. Only the feed on your broker's platform reflects prices at which your orders are executed.

What is a tick?

A tick is a single update in the price feed. It is a new bid, a new ask, or both.

Can the feed be wrong?

Yes. Bad ticks, freezes and gaps happen, especially in fast or thin markets. Platforms and brokers have their own rules for handling them, so check your broker's terms.