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Front running

Front running is trading ahead of a pending order you have advance knowledge of, to profit from the price move that order is expected to cause. It is treated as market abuse.

By Fredrik FilipssonFounder and editor · Two decades in advisory, hospitality and mediaEditorial review by Morten Andersen · Last reviewed 6 December 2025

Last reviewed 6 December 2025 · Educational, not advice

Information, not advice. This page is general information, not financial, investment, legal, tax, or betting advice. Prediction markets carry a real risk of loss. You must be 18 plus or the legal age in your region.
In plain terms

What the term means and how it is used.

Front running is the practice of trading ahead of an order you know is coming, in order to profit from the price move that order is likely to cause. The classic case is a broker or insider who can see that a large buy order is about to hit the market. Knowing that a big purchase tends to push prices up, they buy first for their own account, let the large order move the price, and then sell into that move. The gain comes not from any view of the underlying event, but from a privileged glimpse of someone else's pending trade.

What makes this abusive rather than clever is the source of the advantage. The information being used is not public. It is knowledge of another party's intended order, often gained through a position of trust such as handling a client's instructions or operating part of the trading system. Acting on it takes value from the person whose order moves the price, who ends up trading at a worse level because someone stepped in front of them. That is why it is grouped with other forms of market abuse rather than with ordinary competition.

It helps to draw a clean line between front running and fast, legitimate trading. Reacting quickly to news that everyone can see, or to a price that has already moved on the public order book, is normal market activity. The difference is whether the edge comes from public information or from advance, non public knowledge of a specific order. Speed alone is not the wrong. Misusing private knowledge of another party's intent is. This distinction is why regulators focus on what information was used and how it was obtained, not on how quickly a trade was placed.

On regulated venues, front running is generally prohibited, and brokers handling client orders owe duties that forbid trading ahead of those orders. Exchanges monitor for it, and it can carry serious consequences including penalties and loss of access. The exact legal treatment depends on the venue, the jurisdiction, and the precise facts, and this page is general information rather than legal advice. The term also appears in discussions of decentralized markets, where the ordering of transactions can sometimes be exploited, a related but technically distinct problem.

For an ordinary participant, the useful takeaway is awareness rather than imitation. Knowing that front running exists helps you understand why fair venues guard the confidentiality of pending orders, why rules around order handling matter, and why a sudden adverse move just before a large order fills can be a red flag worth questioning. It is a reason to prefer venues with clear conduct rules and strong oversight, not a tactic to copy.

A worked example

Imagine someone handling orders sees a client about to buy a large block of a contract trading near fifty cents. Knowing that the size will push the price up, they buy for themselves first, the client's order then lifts the price to fifty four cents, and they sell into it. The client pays more than they should have, and the gain came from advance sight of a private order, not from any read on the event. That misuse is what makes it front running.

Illustrative only. Numbers are examples, not a quote or a prediction, and this describes prohibited conduct to explain it, not to encourage it.

A note on risk,

Front running is prohibited conduct on regulated venues, described here so you can recognize it, not copy it. Prediction markets can lose you money. Stake only what you can afford to lose, never to chase a loss, and never on borrowed money. In the United States you can call or text the helpline on 1-800-GAMBLER or visit ncpgambling.org.

Common questions

Answered plainly.

What is front running?

Front running is trading ahead of a pending order you have advance knowledge of, so you profit from the price move that order is expected to cause. It misuses non public information about someone else's intended trade and is treated as market abuse on regulated venues.

Why is front running considered abusive?

It takes value from the person whose order moves the price, using information they did not consent to share. Because it relies on a privileged view of pending orders rather than a genuine market view, regulators and exchanges prohibit it and can penalize it.

Is front running illegal?

On regulated exchanges and for brokers handling client orders it is generally prohibited and can carry serious consequences. The exact legal treatment depends on the venue, the jurisdiction, and the facts, so this is general information, not legal advice. Verify the rules that apply to you.

How is front running different from normal fast trading?

Reacting quickly to public information is ordinary trading. Front running depends on advance knowledge of a specific pending order that is not public. The wrong is the misuse of that private knowledge of another party's intent, not speed in itself.

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