Margin trading is the practice of borrowing from your broker or exchange to take a position that is larger than your cash balance. You post collateral, called margin, and your provider lends the rest so you can buy or short more than you could with cash alone.
It increases your market exposure and your sensitivity to price moves. Profits can build quickly, and losses can too. Because you are using credit, you may pay interest or funding and can face forced closure if your equity falls too far.
What happens when you place a margin trade
In practical terms, you open a margin account, deposit funds and receive a buying power that is a multiple of your cash. The required deposit to open a trade is the initial margin. The trade then runs with continuous checks that your equity still covers risk.
A simple long example makes the mechanics clear:
- You deposit £1,000.
- Your provider allows 5 to 1 leverage on a given product.
- You buy £5,000 of shares using £1,000 margin and £4,000 borrowed.
If the shares rise 2 percent, the position gains £100. Your return on cash is roughly 10 percent before costs because you controlled £5,000 with £1,000. If the shares fall 5 percent, the position loses £250, which is a 25 percent hit to your equity. Small price changes get magnified into larger percentage outcomes on your account.
Short selling on margin flips the logic. You borrow the shares, sell them, then aim to buy back lower. The collateral and risk controls are similar, but there can be extra borrow fees and the risk is asymmetric because a short can, in theory, rise without limit.
Where you encounter margin trading across markets
Margin is embedded in many instruments and venues, though the exact behaviour varies by provider and jurisdiction.
- Equities and ETFs: brokers may let you buy on margin and short sell, subject to eligibility rules, interest and stock borrow availability.
- Futures: exchange-traded futures use margin by design. You post a fraction of the contract value and gains or losses are settled daily, known as mark to market.
- FX and CFDs: retail platforms often offer sizeable leverage with overnight financing or funding charges. Contract terms differ by firm.
- Crypto: many exchanges offer spot margin and perpetual futures with cross or isolated margin settings, auto-liquidation engines and funding payments between longs and shorts.
- Options: buying options does not use margin in the same way because you pay the full premium. Writing options usually requires margin to cover potential obligations.
The margin levels that keep a trade alive
Two thresholds govern most margin accounts:
- Initial margin: the minimum you must post to open a position. It sets your starting leverage.
- Maintenance margin: the minimum equity you must retain to keep the position open. Fall below it and your broker will demand action.
Account equity moves with unrealised profit and loss, plus fees and interest. If equity drops under maintenance levels, you may receive a margin call asking you to add funds or reduce exposure. If you do not, the provider can close positions to protect against further losses. Some venues liquidate automatically once a preset threshold is breached.
Different products use different formulas. A common idea is the equity-to-exposure ratio. If that ratio falls under a required percentage, action is triggered. In futures, exchange rules and clearing houses set the parameters. In retail margin accounts, each broker can set its own policy within local regulations.
Leverage, position size and risk control
Leverage multiplies outcomes, so sizing is critical. Choosing a lower multiple gives you more room for the market to swing before your equity is squeezed. Choosing a higher multiple reduces that buffer and makes liquidations more likely if prices gap.
Useful practices include:
- Start with the maximum loss you can tolerate, then work backward to pick a position size and leverage that fit that limit.
- Use stop orders to cap downside. A stop is not a guarantee at a price if the market jumps, but it can help.
- Prefer liquid instruments and hours with deeper order books to limit slippage.
- Understand cross versus isolated margin. Cross shares one equity pool across trades, which can stabilise a wobbling position but puts more capital at risk. Isolated fences each trade, which can contain damage but may lead to quicker liquidation on that line.
- Watch for trading halts and price bands. Events like limit up or limit down can make exiting harder during a fast move.
Costs, interest and funding
Because margin uses credit, there are running costs that affect P&L:
- Interest on borrowed cash for long positions, often charged daily.
- Stock borrow fees for shorts, which can vary widely depending on availability.
- Financing or funding on derivatives. CFDs typically charge a daily financing rate. Perpetual futures use funding payments between longs and shorts that can flip direction over time.
- Commission, exchange fees and the spread between bid and ask.
Costs vary by provider and product design. Read the schedule carefully, as small daily charges compound over holding periods and can turn a flat price into a negative return.
Worked example: a small account at 5 to 1
Suppose you have £2,000 in a margin account. The broker allows you to trade at 5 to 1 on a liquid index CFD. You open a £10,000 long position. Initial margin is £2,000. Ignore commissions for simplicity.
Scenario A: the index rises 3 percent. The position gains £300. Your equity becomes £2,300. Return on cash is roughly 15 percent before financing.
Scenario B: the index drops 8 percent. The position loses £800. Your equity falls to £1,200. Your equity-to-exposure ratio is now £1,200 ÷ £10,000 = 12 percent. If the broker’s maintenance level for this product is 15 percent, you are below it. You would be asked to add funds or cut size. If you do nothing and the market keeps sliding, the broker may reduce or close the position to restore coverage.
This example shows why margin magnifies both sides. A routine swing can put pressure on a highly geared account, even when the longer term view is unchanged.
How margin trading differs from other ways to get leverage
There are several ways to scale exposure, each with its own trade-offs:
- Cash plus margin loan: you borrow directly against your account and pay interest. You face calls and potential liquidation when equity falls.
- Derivatives with embedded leverage: futures and CFDs deliver exposure for a fraction of the notional. Financing is built into margins or daily funding rather than a simple loan rate.
- Leveraged funds: some ETFs aim for a fixed multiple of an index. Financing is inside the product and rebalanced daily, which can create path-dependent returns that differ from a DIY margin trade.
Whichever route you take, the common thread is magnified sensitivity to price moves. Managing size, costs and exit plans is as important as being right on direction.