Markets

How to Trade CFDs in Practice: From Asset Choice to Exit

Astron Team · 09/24/2026 · 4 min read

CFD stands for contract for difference: an instrument where you don't buy the asset itself, but a contract whose result reflects the difference between the entry price and the exit price. This lets you trade both rises and drops in stocks, indices, currencies, and commodities without needing to physically hold the asset. This guide focuses on the practical side — the steps and the numbers of a trade — leaving the broader theory for those who already understand the basic mechanism.

Step 1: understand what margin actually means

When you open a CFD, you don't deposit the position's full value — only a margin, a percentage of it. Suppose a CFD on a stock trading at R$ 100.00, with a required margin of 20%. To control a position of 100 units (R$ 10,000.00 in exposure), you only need to deposit R$ 2,000.00. That other R$ 8,000.00 is, in practice, borrowed through the leverage built into the contract — which amplifies both the gain and the loss relative to the deposited capital.

Step 2: calculate the result before entering, not after

Continuing the example: if the stock rises to R$ 103.00, the gain on the position is R$ 300.00 (100 units × R$ 3.00). On the deposited margin of R$ 2,000.00, that represents a 15% return — much more than the asset's 3% rise, because of leverage. The mirror is also true: if the stock falls to R$ 97.00, the R$ 300.00 loss also represents 15% of the deposited margin. Doing this math before opening the position avoids the surprise of seeing a small change in the asset's price turn into a large loss on the available capital.

Step 3: set the stop loss as part of the entry, not as a plan B

Since leverage amplifies the result, an adverse move bigger than expected can quickly eat up the available margin — in extreme cases, triggering a margin call, where the broker asks for more deposit or closes the position automatically to contain the loss. Setting the stop loss level at the moment of entry, calculating what that represents in money and as a percentage of the margin, is what keeps a single trade from compromising the rest of the capital available for trading.

Step 4: consider the cost of keeping the position open

CFDs held beyond the same day usually generate a cost (or, more rarely, a credit) for rollover, charged for keeping the leveraged position open overnight. On a R$ 10,000.00 exposure position with a 0.03% daily rollover rate, the daily cost would be R$ 3.00 — small on its own, but it adds up on positions held for weeks, reducing the trade's net result.

Step 5: size the position by margin, not by exposure

A common mistake is sizing the trade by thinking only about the total exposure (the R$ 10,000.00 in the example) without considering that the real risk of a quick loss is tied to the smaller margin (the R$ 2,000.00). As a rule of thumb, many traders limit the risk of each trade to a small fraction of the total capital available for trading — 1% to 2%, for example — calculated on the distance between the entry price and the stop loss, not on the contract's total size.

Step 6: track the position, not just the asset's price

Once the position is open, what matters to monitor isn't just the asset's quote, but how much free margin remains in the account — the amount not yet committed to the open position. If several leveraged trades are opened at the same time, free margin can drop quickly even without any single one hitting its individual stop, increasing the risk of a combined margin call. Checking this number alongside the price is part of monitoring, not a secondary detail.

Putting it all together

Trading CFDs in an organized way means, in practice, calculating three numbers before any entry: how much margin the position requires, how much you lose if the stop is hit, and how much it costs to hold the position for the planned time. Platforms like Astron show these values directly on the order screen, which helps with this math before confirming — but the decision to trade within these limits remains the trader's, and the leverage built into the CFD means losses can, in some cases, exceed the amount originally deposited as margin. Because of that, CFDs are usually recommended only after the trader already understands the asset's behavior well without leverage.