What Is High Frequency Trading: HFT Meaning

What is high-frequency trading?

High-frequency trading (HFT) is automated trading in which computer programs send, change and cancel very large numbers of orders within fractions of a second, aiming to earn very small amounts on each trade.

An algorithm is a set of rules a program follows to decide when to place an order. HFT is a type of API trading or algorithmic trading where speed itself is the main tool.

HFT explained with a hypothetical example

This case is invented to show the mechanics. It is not a description of any real firm or broker.

A share is listed on Exchange A and Exchange B.
For a brief moment, the ask (selling price) on Exchange A is slightly below the bid (buying price) on Exchange B.
An HFT system spots the gap, buys on Exchange A and sells on Exchange B almost at the same instant.
The gain per share is a tiny fraction of the price. The firm repeats this many times a day across many instruments.

This is a form of arbitrage. The gap usually closes within microseconds, so only the fastest systems capture it. If the second order is not filled, or only partly filled, the firm holds an unwanted position and can lose money.

Another common HFT activity is market making. A dealer-style program keeps posting bids and asks, earns the spread, and cancels its quotes as soon as prices move.

The formal definition and edge cases

No single legal definition applies worldwide. Regulators usually describe HFT by these features:

orders are generated by the system without human intervention
infrastructure built to cut latency (delay), such as co-location, where the firm's servers sit inside or next to the exchange data centre
very high message rates, with most orders cancelled rather than filled
very short holding periods, often ending the day with no open position
trading for the firm's own account

Edge cases:

Retail Expert Advisors are not HFT. A program running on MT4 or MetaTrader 5 that opens many trades a day is automated trading. It does not have exchange co-location, so it is not HFT in the regulatory sense.
Latency arbitrage against a retail broker exploits delays in a broker's price feed. Many broker terms restrict it, so check the conditions of your account.
Slow algorithms that split a large order over hours are algorithmic trading but not high-frequency.

Where you see the term

News: reporting on a flash crash, sudden liquidity gaps, or exchange circuit breakers.
Exchange and regulator reports: rules on order-to-trade ratios, speed bumps and co-location fees.
Broker documents: execution policies and terms that mention A-book and B-book models or prohibited trading methods.
Debates on fairness: claims of front running, where speed is used to trade ahead of other orders.

Retail traders face HFT indirectly, through tighter spreads in calm markets and faster price jumps around news. Leveraged CFD and forex trading can lose money fast, whatever the speed of your execution. See risk management.

Frequent questions

What does HFT mean?

HFT stands for high-frequency trading: automated trading that places and cancels huge numbers of orders very quickly to earn small amounts per trade.

Can a retail trader do HFT on MT4 or MT5?

Not in the strict sense. Retail platforms allow automated trading, but they lack the exchange-level speed and co-location that define HFT.

Is HFT the same as scalping?

No. Scalping means holding trades briefly, whether manually or with a program. HFT works at much higher speed and order volume.

Does HFT guarantee profit?

No. Gaps close fast, orders can fail, and systems can malfunction. Losses can be large.