Futures arbitrage: basis and funding

The ETH perp on Bybit pays you 0.03% every 8 hours just for holding a short, while the same coin sits flat on Binance spot. Buy the spot, short the perp, and you collect that payment three times a day without betting a cent on where ETH goes next. That is futures arbitrage: profiting from the gap between a futures price (most often a perpetual) and a related price - spot, the index, or the same perp on another exchange. Unlike spot arbitrage, the coin usually doesn't move between exchanges. The route closes through price convergence or through funding payments instead.

That makes futures arbitrage largely delta-neutral: the position doesn't depend on market direction, and profit comes from a structural gap rather than guessing where price goes. The price you pay for that comfort is leverage liquidation risk and dependence on the funding schedule. Below: the three mechanics of futures arbitrage (basis, perp funding, intra-exchange vs index), cross-venue funding divergence, a step-by-step entry, the role of a bot, a worked example, and an FAQ.

Basis: futures↔spot

Basis is the gap between a futures price and the spot price of the same asset. When the future trades above spot (contango), you open a delta-neutral position: buy spot and short the future for the same size. Price moves, both legs offset each other, net market exposure ≈ 0. The profit is captured two ways:

• Convergence to expiry (for quarterly futures): by the settlement date the futures price converges to spot, and the basis closes in your favor.
• Funding (for perpetuals): a perp never expires, so it's tethered to spot by the funding-payment mechanism (see below).

This is the calmest mechanic. Market direction is irrelevant, and you compute the clean basis gap minus the fees on both legs. It is the natural next step after spot arbitrage: same delta-neutral idea, but the gap closes on a schedule instead of through a coin transfer.

Perp funding: how it works

A perpetual future has no expiry date, so the exchange keeps its price near spot via the funding rate - a periodic payment between longs and shorts. The cadence varies by venue: Binance, Bybit and OKX settle BTC and ETH every 8 hours, while many alt perps and exchanges like Bitget or Gate run 4-hour or even 1-hour windows on hot tickers.

• If the perp trades above spot (more longs) → funding is positive → longs pay shorts.
• If the perp is below spot → funding is negative → shorts pay longs.

Funding arbitrage captures exactly this payment: you hold spot (or the opposite perp) as a hedge and collect funding from whichever side pays, staying delta-neutral. Imagine a meme-coin perp on MEXC running +0.25% per 8h during a hype week. Short the perp, buy the spot, and you bank that 0.25% three times a day while the price does whatever it likes. The key nuance is the cadence: you must hold the position right at the funding settlement, and the rate is normalized differently on 8h/4h/1h exchanges. The detailed math of accrual and rate normalization is in funding cadence: the math of rates, and the practice of harvesting it is in funding arbitrage.

Intra-exchange arbitrage: futures vs index

A separate intra-exchange mechanic is the gap between the perp price and its fair/index price (the reference price the exchange uses to compute funding and liquidations) inside a single exchange. When a sharp move runs through the perp's order book (a liquidation cascade, thin liquidity), the mark/last price detaches from the index. That's a window for intra-exchange arbitrage: enter against the deviation expecting the perp to return to the index, all within one order book, with no coin transfer between exchanges.

These windows are tiny (fractions of a second) and fast, so this is usually the domain of an intra-exchange arbitrage bot. A human physically can't enter and exit at cascade speed. The bot monitors the perp − index spread and executes when the deviation covers fees. It's a close cousin of triangular arbitrage by nature, all inside one venue, with no D/W risk.

Cross-venue funding divergence

The most popular cross-venue mechanic is funding-rate divergence between exchanges. On Binance the BTC perp pays +0.03% per period, on OKX it's −0.01% at the same moment. You:

• go long the perp where funding is negative (you receive the payment),
• go short the perp where funding is positive (you receive the payment),

both legs on the same coin and size → net market exposure ≈ 0, while funding drips in from both sides. The coin doesn't move between exchanges, you only need margin on both venues. This is cross-venue but without the coin-transfer D/W risk (unlike spot–spot). The risks here are different: leverage liquidation and a change in the funding rate itself by the next settlement.

Step by step: a funding route you can run today

Here is a concrete cross-venue funding play with real-ish numbers. Adjust the figures to live data before you touch it.

1. Find the divergence. Scan funding across venues. Say the ARB perp pays +0.06% per 8h on Bybit and −0.02% on Gate. The spread you can collect is 0.08% per period, roughly 0.24% per day.
2. Size the legs equally. Put $2,000 notional on each side. Long ARB perp on Gate (collects the negative funding), short ARB perp on Bybit (collects the positive funding). Same coin, same notional, so net delta ≈ 0.
3. Keep leverage low. Use 2x, not 10x. Lower leverage pushes your liquidation price far from the mark, which is the whole point of staying alive through a wick.
4. Check both margins before the settlement. Funding pays at the exact settlement timestamp. If a leg is close to liquidation, top up margin or trim size first.
5. Hold through the settlement, then re-evaluate. Funding can flip by the next window. If the spread is gone, close both legs. On $4,000 total, 0.08% per period is about $3.20 per settlement, roughly $9.60 a day while the spread holds.
6. Net out the fees. Four taker fills at ~0.05% on $2,000 each cost about $4 round-trip. That is more than one settlement, so this only works if you hold for several periods or the spread is wide. A few hours of funding can be eaten entirely by entry and exit costs.

That last point is the difference between a real edge and a screenshot. A 0.08% funding spread is not 0.08% of profit - it is 0.08% per period minus four taker fees minus the risk that the rate flips. Run the full count before you size up.

Example: a futures↔spot basis route

Take a quarterly ETH future in contango (future above spot). $10,000 of capital per leg, delta-neutral, and the coin doesn't move between exchanges, both legs on one venue.

ETH spot:            $3,000.0
ETH future (3 mo):   $3,048.0   → basis +1.6% to expiry (~48 days)
Route: LONG $10k spot + SHORT $10k future (delta-neutral)

Basis capture to expiry (the future converges to spot):
  Basis +1.6% on $10,000          = +$160 (if held to convergence)

Entry/exit cost (4 takers ~0.05% × $10k):
  −$20 once to open+close both legs
──────────────────────────────────
Net ≈ +$140 over ~48 days of holding (~10.6% APR per leg),
if the basis converged and neither leg is liquidated

The difference from a funding route is clear: here the profit is locked in by the basis at entry and realized at expiry through price convergence, rather than dripping in as periodic payments. Market direction is irrelevant, the legs offset each other, and all that matters is that the future converges to spot by the settlement date. The risk here is an early liquidation of the short leg on a sharp pump (if collateral is thin) and basis divergence on a thin asset. That's why the fair price, the expiry date and the margin mode matter more than a "big percent" of basis in the moment.

Realistic expectations

If you are coming from a YouTube thumbnail promising "risk-free 40% APR," recalibrate before you fund an account. Delta-neutral does not mean risk-free, and the numbers in the wild are smaller than the screenshots.

• Your first weeks are tuition. You will misjudge a fee, hold a leg too long, or watch a funding rate flip the period after you enter. Start with $50-200 per leg, not your whole stack. The goal early on is to make the mechanics automatic, not to get rich.
• The clean spreads are crowded. A fat BTC or ETH funding divergence on Binance or OKX gets arbitraged away fast. The persistent edges live on smaller alts, newer listings, and venues like MEXC, Gate or Bitget where fewer bots are watching. Those also carry thinner liquidity and uglier liquidation behavior.
• Liquidation is the only thing that can really hurt you. A delta-neutral book bleeds slowly from fees and rate drift, which is annoying but survivable. One liquidated leg on a violent wick can wipe a month of funding in a minute. Low leverage is not optional.
• Funding is not a fixed yield. A perp paying +0.06% now can pay 0% or flip negative by the next settlement. Treat quoted APRs as "right now," not "forever," and re-check at every window.

None of this makes futures arbitrage a bad strategy. It makes it a real one. The traders who last are the ones who size small, keep leverage low, and count every fee.

FAQ - futures arbitrage

What is futures arbitrage in simple terms?

It's profiting from the gap between a futures price and the spot/index/another perp price. Usually delta-neutral: you buy one and short the other for the same size, and profit comes from a structural gap (basis or funding) rather than market direction.

What is the basis in futures arbitrage?

The basis is the gap between a futures price and spot for the same asset. In contango (future above spot), you buy spot and short the future. The basis closes by expiry or is held via funding for perpetuals.

How does funding arbitrage differ from basis arbitrage?

Basis arbitrage captures the future's price convergence to spot (especially quarterlies into expiry). Funding arbitrage collects the periodic funding payments on perpetuals while staying delta-neutral. The math of the rates is in funding cadence.

How much leverage should I use for funding arbitrage?

Low, usually 1-3x on the perp leg. The whole point of staying delta-neutral is surviving sharp moves, and high leverage puts your liquidation price right next to the mark. More leverage does not increase the funding you collect on a hedged book, it only brings the liquidation closer.

Do I need a bot for intra-exchange futures arbitrage?

For "perp vs index" windows inside one exchange, yes. They live fractions of a second at cascade speed, and a human can't make it. For cross-venue funding (8/4/1-hour periods) you can manage the position by hand with a good monitor.

Why is futures arbitrage riskier than spot arbitrage?

The main risk is leverage liquidation: on a sharp move one leg can be liquidated before the other offsets it. Spot arbitrage carries coin-transfer D/W risk, futures carries margin risk. That's why margin mode and leverage size are critical.

How much can I realistically make with futures arbitrage?

On crowded majors, single-digit APR after fees is typical. Wider spreads exist on smaller alts and newer venues, but they come with thinner liquidity and bigger liquidation risk. Expect small or negative results while you learn, then modest, compounding returns once your sizing and fee math are tight.

Related: the pillar Crypto arbitrage guide, the math of funding, funding arbitrage, spot arbitrage, cross vs isolated margin, triangular arbitrage and cross-exchange arbitrage. Ready to scan live? Open the scanner and watch live funding across 20+ exchanges in the funding section.