Funding Arbitrage Guide: Delta‑Neutral Funding Capture (with Risk Rules)

1) What funding is (and what it is NOT)

Funding is a periodic payment between long and short perp holders that helps anchor perp price to spot. It’s not free yield: the market can reprice via basis (premium/discount), and funding can flip.

2) The core delta‑neutral setup

The simplest funding capture: hold spot (long) and short the perp of the same asset. If funding is positive, shorts receive funding (exchange-specific). The hedge reduces directional PnL, leaving funding + basis effects.

Execution checklist (before you enter)

• Check funding schedule (when it’s paid) and the current/forecast rate
• Validate order book depth on BOTH legs for your size (entry + exit)
• Model fees: taker/maker + funding settlement + withdrawals (if any)
• Confirm margin mode (isolated vs cross) and liquidation buffer
• Define exits: funding flip, basis convergence, time stop, drawdown stop

Entry rules (quick, practical)

• Prefer limit orders on at least one leg to reduce fees and slippage
• Don’t enter if you can’t exit cleanly (liquidity > headline rate)
• Start with a small test size to validate fills and settlement
• Avoid entering right before major news/volatility spikes

3) Net yield math (simple version)

Capital used depends on margin + spot purchase + any collateral. Don’t compute APY on notional if your collateral is much smaller (it hides liquidation risk).

4) The risks that actually matter

Funding arbitrage fails when the hedge breaks or when the market reprices faster than you can exit. Treat it like an execution strategy, not a passive product.

Exit playbook (define BEFORE entry)

• Funding flip: exit if funding turns meaningfully negative for your leg
• Basis widens: exit if perp premium/discount moves beyond your model
• Time stop: exit if edge doesn’t persist after N intervals
• Risk stop: exit if liquidation buffer is threatened (don’t gamble on mean reversion)

Alerts to set (simple, effective)

• Funding rate change / forecast change
• Basis widening beyond threshold
• Price move % in short window (volatility spike)
• Margin ratio / liquidation distance (buffer alert)

Risk rules (copy/paste)

• Use isolated margin unless you intentionally want cross risk
• Keep a liquidation buffer; avoid running “max leverage” to juice APY
• Size so your hedge can exit with minimal slippage (liquidity first)
• Set alerts for funding changes and rapid basis widening
• Prefer venues with reliable uptime and deep books for the pair

5) Quick example (sanity check)

If your round-trip fees + slippage are higher than a few days of expected funding, you’re not capturing yield — you’re paying it.

6) When to skip funding arbitrage

• Funding is unstable or already compressing (rate drops quickly)
• Order books are thin for your size (exit will cost too much slippage)
• Margin/liquidation buffer is tight (you’re “forced” to hold through wicks)
• Borrow costs (or spot carry costs) offset most of the funding
• You don’t have a clear exit rule for funding flips or basis expansion

7) Position sizing and margin (practical rules)

Most blowups come from sizing too big for the exit. Treat liquidity and liquidation buffer as the real constraints, not the headline funding rate.

Sizing rules (simple, robust)

• Start small: size so you can fully exit in < 1–2 minutes without sweeping multiple levels
• Keep a liquidation buffer: don’t run max leverage just to inflate APY
• Prefer isolated margin for clean risk accounting (cross only if you know why)
• Use limit orders where possible; don’t pay taker fees on both legs by default
• Have a time stop: if edge disappears, exit—even if it’s “almost next funding”

FAQ (quick answers)

• Do I need leverage? No—leverage improves capital efficiency but increases liquidation risk.
• Is this the same as cash & carry? Related: cash & carry focuses on basis + convergence; funding capture focuses on funding payments.
• How often should I rebalance hedge? When delta drifts materially or when basis/funding regime changes.