Guide · 8 min read
Sports trading explained: back-to-lay, green-up and commission
Sports trading means buying and selling a price on a betting exchange, much like a trader buys and sells a share, and closing the position before the match is decided. It sounds like a way around the risk of the result. It is not quite that. Here is how back-to-lay and scalping work, the green-up maths with real numbers, what commission does, why most traders lose and whether trading is even available where you live.
Updated 22 October 2026
Contents
What sports trading is
On a betting exchange you can do two things: back an outcome (bet that it happens) or lay it (bet that it does not, acting as the bookmaker for someone else). Our guide to back and lay bets covers the basics.
A trader backs at one price and lays at another, or the other way round, aiming to profit from the movement of the price rather than from the result. If you back at high odds and later lay at lower odds, you can lock in a profit whatever happens. If the price moves the wrong way, you lock in a loss.
Back-to-lay and green-up: a worked example
Before kick-off you back Team A for €100 at odds of 3.00. After 20 minutes Team A scores, and the price shortens to 2.50. To close the trade with the same profit on every outcome ("green up"), you lay Team A at 2.50. The lay stake is:
lay stake = back stake × back odds ÷ lay odds = 100 × 3.00 ÷ 2.50 = €120
| Result | Back bet | Lay bet | Total |
|---|---|---|---|
| Team A wins | +€200 | −€180 | +€20 |
| Team A does not win | −€100 | +€120 | +€20 |
The lay loses €120 × (2.50 − 1) = €180 if Team A wins. Either way you are €20 ahead before commission. Exchanges charge commission on your net winnings in a market; with a 5% rate that is €1, leaving €19.
Now the other case: Team A concedes instead, and the price drifts to 3.60. Closing the position means laying 100 × 3.00 ÷ 3.60 = €83.33. If Team A wins: +€200 − €83.33 × 2.60 = −€16.67. If not: −€100 + €83.33 = −€16.67. A "red-up": a locked-in loss. No commission is charged on a net loss.
The key point: green-up maths only spreads a gain or loss evenly. It does not create one. Whether you win depends entirely on whether you predicted the price movement correctly.
Scalping: small ticks, many times
Scalpers try to earn one price step ("tick") at a time. For example: back €500 at 2.02, then lay €505 at 2.00. If the selection wins: +€510 − €505 = +€5. If it loses: −€500 + €505 = +€5. After 5% commission, about €4.75.
That only works if someone takes your bets at those prices, which needs deep liquidity, and if the price does not jump several ticks against you while you wait. One goal, red card or break of serve can move a price by far more than the few ticks you were trying to earn, so a single bad trade can wipe out dozens of good ones.
Commission: the cost that adds up
Exchanges earn by taking a percentage of each customer's net winnings per market. Betfair, for example, assigns each customer a base rate, uses 5% in its own examples and offers discounts based on activity. In some regions, very profitable customers pay an additional premium charge.
Commission matters most for small-margin trades. On the scalping example above, 5% takes €0.25 of a €5 gain. On a green-up of €20 it takes €1. Because you only pay on winning markets, commission never makes a losing trade worse, but it shrinks every winner, so you need more winners to break even.
Why most traders lose
An exchange is a market between customers. Before commission, every euro one trader gains, another loses. After commission, the total is negative, so the average trader must lose money. To be on the winning side consistently, you need to be faster or better informed than the people you trade against, and they include:
- automated trading software reacting in milliseconds;
- people at the venue or with faster data feeds than a TV stream, which often runs seconds behind;
- professional syndicates with their own pricing models.
Exchanges also add a short delay to in-play bets, so you cannot simply react after an event. Many beginners take a few winning trades as proof of skill, then size up. Our guide to cognitive biases explains why that feels so convincing, and betting variance why a few trades prove little.
Can you trade from Austria or Slovakia?
For most of our users, this is the deciding question. As of October 2026:
- Austria: we know of no betting exchange that accepts Austrian customers. Betfair's own country-closure FAQ lists Austria as not available, and Matchbook restricts Austria.
- Slovakia: only operators licensed by the regulator ÚRHH may offer online betting, and none of them runs an exchange. Betfair and Matchbook are on the ÚRHH list of prohibited offers.
We describe this neutrally; it is not legal advice. Using a provider that is not available in your country can breach its terms (with the risk of losing your balance) and, depending on the country, local law. More detail is in our guide to betting exchanges. Exchange prices still matter as a reference for fair odds, as we explain in sharp vs soft bookmakers.
Sports trading vs arbitrage
| Sports trading | Arbitrage (sure bets) | |
|---|---|---|
| Where | A betting exchange | Two or more bookmakers |
| Needs a forecast? | Yes, of the price movement | No; it uses existing price differences |
| When the result is locked | Only after you close the trade | As soon as all legs are placed and accepted |
| Typical margin | Depends on your skill; can be negative | Usually 1 to 2% of total stake |
| Main risks | Price moves against you, speed, commission | Odds change before the second leg, voided bets, account limits |
| Available in AT/SK | No known exchange for residents | Yes, with bookmakers available locally |
Arbitrage and hedging use similar maths, but the decision is different: a sure bet is placed only when the prices already add up, so you are not betting on where a price goes next. It still carries practical risks, and bookmakers may limit accounts that take sure bets often.
Frequently asked questions
What does green up mean in sports trading?
It means closing a trade with an opposite bet sized so you get the same profit whatever the result. Example: back €100 at 3.00, lay €120 at 2.50, and you are €20 ahead on every outcome before commission.
Does greening up remove the risk?
No. Green-up only spreads a gain or loss evenly across outcomes. If the price moves against you, you lock in a loss, and commission reduces every winning trade.
Can I use a betting exchange in Austria or Slovakia?
As of October 2026 we know of no exchange that accepts Austrian customers, and no ÚRHH-licensed operator in Slovakia runs one. Betfair and Matchbook are on the Slovak list of prohibited offers.
Is arbitrage the same as sports trading?
No. Trading needs you to predict how a price will move on an exchange. Arbitrage uses price differences that already exist between bookmakers, so it needs no forecast, but it has its own risks such as odds changes, voided bets and limits.
Sources
- Betfair: Betfair charges (commission, discount, premium charge)
- Betfair: Country closure FAQs
- ÚRHH (Slovakia): Zoznam zakázaných ponúk (list of prohibited offers)
- ÚRHH (Slovakia): licensed online operators
- Levitt, S. D. (2004): Why are gambling markets organised so differently from financial markets? The Economic Journal 114(495)
As of October 2026. Calculations by ArbVantage; the examples are illustrative and ignore partial matching.
Betting involves risk, sure bets and trading included: odds change, bets get voided and accounts get limited. Only bet money you can afford to lose. Our responsible gambling page lists free help.
Not betting, legal or tax advice. 18+. As of October 2026. See our disclaimer.