Crypto Perpetual Futures: How They Work and What They Cost

You are entering a price contract. A BTC/USDT perpetual long gains when its closing price is above its entry price; a short gains when the opposite happens. The position has a quantity, an entry price and collateral supporting it. Those are the ingredients of the trade, even if the exchange makes opening one look as simple as pressing Buy.

A BTC position is not a withdrawable BTC balance

Suppose the position represents 0.1 BTC. That is how much Bitcoin price exposure you hold, not a promise to receive 0.1 BTC in your wallet. On a linear USDT-settled contract, the result is paid in USDT. If you want Bitcoin to send to another wallet, you need an actual BTC balance, obtained separately through a purchase, transfer or another legitimate source.

This distinction matters when comparing a perp with a spot purchase. A trader who wants to keep coins for several years owns a different thing from a trader trying to profit from a two-day price movement. A perp can express that shorter price view without purchasing the full amount of coins. It also introduces payments and forced-closure rules that an unborrowed spot holding does not have.

No scheduled expiry does not mean a guaranteed lifetime

A dated future has a scheduled settlement date. A perpetual normally does not, so you do not have to replace it with next month’s contract merely to keep the same exposure. But you must still meet its margin requirements. A venue can also discontinue a market. “Perpetual” describes the contract’s normal schedule, not a right to stay in a trade forever.

There is also a difference between keeping the contract and keeping your original trading plan. A position held longer than intended accumulates more funding events and can face changed market conditions. An order opened for a short move should not quietly turn into an indefinite holding just because the ticket has no expiry field.

Start with the instrument name and the order unit. Two markets can both contain “BTC” yet settle in different assets or interpret the quantity box differently. An amount of 10 may mean ten contracts, ten dollars of contract value or ten BTC. The confirmation should make the resulting exposure unambiguous before any money is committed.

Contract count, coin quantity and position value

The OKX specification reviewed for this guide lists a BTC/USDT perpetual contract size of 0.01 BTC and settlement in USDT. Ten such contracts represent 0.1 BTC. At an illustrative entry price of 80,000 USDT per BTC, their opening value is 8,000 USDT. That conversion is the bridge between the exchange’s contract count and the quantity used in our calculation.

A useful error check is to read the total position value aloud. If you meant to risk a small amount and the preview shows exposure many times larger than expected, correct the quantity or its unit. Reducing the leverage selector alone may simply require more collateral for the same oversized trade.

The price used for liquidation can differ from the chart

The last traded price records the latest match. The mark price is the exchange’s risk reference, designed to avoid basing liquidations on one unusual execution. OKX documents mark-price-based risk checks. A chart showing the last price therefore may not tell you exactly how close the position is to liquidation.

The index is another reference: it represents the underlying market using the venue’s stated inputs. You do not automatically trade at the index or mark. Your execution still depends on the orders available when yours reaches the market. A displayed reference price is not an executable offer for your entire quantity.

Here is a complete hypothetical trade with every amount in USDT. Start with 1,000 USDT in an otherwise empty account. Open a 0.1 BTC long at 80,000, using 10× leverage and 800 USDT of initial margin. Assume a 0.05% entry fee, a 0.05% exit fee and one positive 0.01% funding event. These are stated calculation inputs, not a promised account fee or a forecast funding rate.

Opening reserves margin; it does not spend the whole position value

The opening execution costs 8,000 × 0.0005 = 4 USDT. The account’s net value is now 996 USDT before any price change. Of that, 800 supports the position, leaving 196 not assigned to it in this simplified ledger. A real ticket may also reserve an estimated closing fee; reserved funds remain yours unless a charge or loss actually uses them.

You have not paid 8,000 USDT to acquire Bitcoin, nor should you subtract 800 as if it were a trading loss. Margin is collateral committed to the position. Tracking it separately from charges prevents a common mistake: counting returned collateral as profit when the trade closes.

Funding is assessed on the position at the event

Assume the mark is 80,000 at the single funding assessment. Position value is still 8,000 USDT, so positive 0.01% funding costs this long 0.80 USDT. Its account value becomes 995.20 before subsequent price movement. The example uses only one event; a position spanning several assessments needs each payment recorded separately.

Closing realizes the price result and releases collateral

The entire 0.1 BTC position fills at 81,000. Price profit is 0.1 × (81,000 − 80,000) = 100 USDT. The closing value is 8,100, so the assumed exit charge is 4.05 USDT. Final account balance: 1,000 + 100 − 4 − 0.80 − 4.05 = 1,091.15 USDT. With no other positions or reservations, the position’s remaining collateral is no longer tied up.

The net gain is 91.15 USDT, or 9.115% of the original 1,000 USDT account. Relative to the 800 initial position margin, the same net gain is about 11.39%. Those percentages answer different questions. Neither changes the 91.15 that the trade added to the account, and the 10× selector must not be multiplied into the profit a second time.

If the close instead filled at 79,000, the price result would be −100 USDT and the exit fee 3.95. With the same opening fee and funding, the balance would be 891.25, a loss of 108.75. Fees make the losing result worse just as they reduce the winning result. Positive funding does not disappear because your long is unprofitable.

There is no universal overnight price for a perpetual. Trading fees attach to executions; funding attaches to the contract’s payment events while you hold the position. Some account arrangements can create additional borrowing costs, but a USDT perp funded with sufficient USDT collateral should not automatically be described as a cash loan charging hourly interest.

Read the sign, the interval and the amount

For the OKX mechanism cited here, positive funding means longs pay shorts and negative funding reverses the direction. Its default assessment interval is eight hours, with shorter intervals possible for individual contracts and adjustments under specified conditions. Use the particular market’s countdown and interval rather than treating every rate on the website as the same length of time.

On a constant 8,000 USDT position, three assessments at +0.01% would cost the long 2.40 USDT. If the middle event were −0.02%, the three cash flows would instead be −0.80, +1.60 and −0.80: zero net funding. The actual result requires the value of the position at each event, which may also move. Multiplying a single current rate across the next week is a scenario, not a known bill.

A negative rate can make a long receive money while its price position loses substantially more. Likewise, a short earning positive funding may face a rising coin price. Funding is one line in the account result, not a substitute for calculating directional profit and loss.

Closing around the countdown is an execution decision

An unfilled limit order does not remove the position from a funding assessment. Only the executed close changes the quantity still exposed. OKX also notes that assessment can take time to complete, so treating a displayed second as a guaranteed free entry window is unreliable. The completed payment record is the useful evidence of what was charged.

Even when you can close before an event, avoiding 0.80 USDT of funding is not automatically worthwhile. Crossing the spread, paying another pair of trading fees to reopen, and missing part of the price move can cost more. For a trade you already wanted to exit, timing may be helpful; for an unchanged position thesis, the full replacement cost belongs in the comparison.

A green price result can still produce a negative account result. With the same 0.1 BTC trade, an exit at 80,050 earns 5 USDT before charges. Entry commission is 4, exit commission is 4.0025 and funding is 0.80. Net result: a loss of 3.8025 USDT. That is why a small winning move is not necessarily a profitable completed trade.

Under these fixed assumptions, the long needs an exit of about 80,088.05 USDT to cover all three charges. The exact threshold is slightly different from adding 8.80 to an arbitrary profit target because the exit fee itself grows with the exit value. Another funding event or a different maker/taker mix changes the threshold again.

Average fills belong in the calculation

A 0.1 BTC order may execute in several pieces. If 0.04 BTC fills at 80,000 and 0.06 BTC at 80,020, the average entry is 80,012. It is not the simple midpoint of 80,010 because more quantity filled at the higher price. Closing the entire position at 81,000 would then produce 98.80 USDT of price profit, rather than the 100 assumed in the original example.

Use completed fills when reviewing a trade. A market-order preview is useful for deciding whether to submit an order, but it is not the final price record. For orders with mixed maker and taker fills, sum the actual fees rather than applying one advertised percentage to every execution.

This is also how to compare two venues without becoming distracted by fee badges. For a short holding period, entry and exit execution can dominate. For a longer holding period, funding can become material. Compare the same quantity and intended holding window; comparing a tiny order on one venue with a large order on another answers a different question.

These products can express similar market views, but they do not leave you with the same obligations. Compare the asset you hold, what can force an exit, and the carrying cost over your intended holding period. The largest advertised leverage number does not resolve those differences.

Spot margin is relevant if you deliberately want a borrowed-asset structure. For example, shorting through a loan involves borrowing the coin, selling it and eventually obtaining it again to repay. A short perp instead creates negative price exposure through the contract. The cost comparison is borrowing interest versus perp funding and the execution costs of each route, not simply “both allow shorting.”

A dated crypto future can be useful when exposure is intended to end around a known date. Its price may contain a premium or discount to spot, which affects the entry economics even without a conventional perp funding schedule. Keeping the hedge beyond expiry requires another contract or another product. Perps remove that scheduled roll, but they exchange it for a funding rate that can change during the holding period.

For someone who wants to withdraw coins, receive ownership-dependent benefits or use an asset on-chain, a price contract is incomplete. A perpetual can track a token’s price without giving the trader staking rewards, voting rights, airdrop eligibility or the tokens needed to pay network fees. Treat any special distribution by an exchange as a separate product rule, not an automatic right of a futures holder.

Your close order can fill fully, partly or not at all

You do not need to wait for the price to reach your target to close a perp. A market close seeks available execution immediately; a limit close asks for your specified price or better and may remain unfilled. A partial close reduces the remaining quantity, so later price movements and funding apply to a smaller position.

For example, closing 0.04 BTC from a 0.1 BTC long leaves 0.06 BTC open. Profit realized on the closed part does not freeze the result of the rest. Check the remaining position after the execution and resize any protective orders if the platform does not handle that automatically. An old order larger than the remaining trade may behave differently from the close you intended.

On OKX, one-way and hedge modes treat opposing orders differently. A sale can reduce a long in one-way mode, while hedge mode can support separate long and short positions. Using the close control or an appropriate reduce-only instruction is more reliable than assuming that any opposite-side order exits the existing position.

Liquidation is the venue’s margin exit

If the remaining eligible equity cannot support the position, the venue can reduce or liquidate it under its risk rules. This happens before a simple “all margin lost” calculation would suggest because maintenance requirements and costs still have to be covered. A position opened at 10× does not come with a guaranteed 10% adverse move allowance.

A delisting can close an otherwise funded position

OKX’s delisting standards allow automatic settlement of affected futures. They describe an averaging process for the closing reference and allow adjustments in exceptional conditions. The market-specific announcement determines the relevant deadline. This is why an adequately margined position can end even though it never reached its liquidation threshold.

Start with the coin and settlement currency you intend to trade. Compare the executable cost of your quantity on that exact contract, then the collateral needed to keep it open. A low commission is of little use if the exit requires crossing a wide spread.

Before funding an account, establish that it offers that derivatives product to residents of your country. Spot availability and an exchange-wide leverage headline do not answer that question.

• Confirm the contract unit and minimum quantity.
• Compare entry and exit costs for the intended size.
• Find the margin mode, funding clock and close controls before opening.