Understanding the Risks
Arbitrage is not risk-free. Slippage can erode thin spreads, partial fills can leave you with an unhedged position, and exchange downtime can prevent you from closing one leg of a trade.
Market events like flash crashes or extreme volatility can cause spreads to invert rapidly. Network latency between your system and the exchange adds execution uncertainty. Understanding these risks is the first step to managing them.
The full risk surface of perpetual futures arbitrage spans seven distinct categories. Slippage risk: market orders fill against the order book, so thin liquidity turns a 0.10% spread into a 0.03% realized result. Partial fill or hung leg risk: one exchange fills, the other rejects, leaving you directionally exposed. Exchange downtime risk: scheduled maintenance, DDoS, or matching-engine halts can lock one side for minutes. API rate limit risk: bursty signals trigger 429 responses and missed entries. Liquidation cascade risk: a 5–10% wick on a 10x position wipes the margin buffer before you can react. Regulatory risk: jurisdictions can freeze withdrawals or delist pairs overnight. Counterparty risk: the exchange itself can become insolvent (FTX precedent) — your collateral evaporates regardless of position health.
Built-in Safeguards
Arbitron includes multiple safety mechanisms: a Force Close button to immediately close all positions, per-card loss limits (Force Stop and Exit Mode) that automatically stop trading when losses reach your threshold, a circuit breaker that pauses all cards if too many execution errors occur in a short time, and automatic position unwinding when one side of a trade fails.
If one leg of a trade fails to fill, the system automatically attempts to unwind the filled leg. If the unwind also fails, it alerts you via Telegram and sets the card to Error status for manual review.
Force Stop and Exit Mode On Loss serve different roles. Force Stop is a hard ceiling: if cumulative card loss reaches, say, -$50, the card halts and refuses to open new cycles. Exit Mode On Loss is more nuanced — when triggered (e.g. -$20 drawdown), the card stops opening new positions but still permits closing existing ones to capture any mean-reversion. Use Exit Mode for soft cooldowns, Force Stop for hard capital protection. The Killswitch is global: it sends an immediate kill signal over NATS that halts every card across every exchange for your account. The circuit breaker is automatic — if the worker logs more than N execution errors per minute (typically 5), it self-pauses for 60 seconds to prevent runaway loss from a recurring API or connectivity fault.
Position Sizing
Start small. Each card has an Order Size setting that controls how much to trade per cycle. Begin with the minimum to validate your setup works correctly before scaling up.
Diversify across exchange pairs and symbols rather than concentrating on a single setup. This reduces the impact of any single exchange issue or market disruption on your overall portfolio.
Position sizing should be mechanical, not emotional. A practical rule: risk no more than 2% of total account equity on any single cycle, and never concentrate more than 10% of equity on any one exchange (counterparty cap). The Kelly criterion gives a theoretical optimal bet size — f* = (bp − q) / b where p is win rate, q is loss rate, b is win/loss ratio — but for arbitrage with thin edges most professionals use half-Kelly or quarter-Kelly to survive drawdowns. Diversify across at least 4–6 exchange pairs and 3+ symbols; correlated wicks on a single pair can wipe a concentrated book. Match your account tier rules: at lower VIP levels keep order size small to qualify for volume-based fee reductions over time rather than chasing single large fills.
What Can Go Wrong
Exchange maintenance windows can occur without warning, temporarily disabling trading. Liquidity can dry up on smaller pairs during off-hours, causing excessive slippage. API rate limits can delay order placement during high-activity periods.
Extreme volatility events (liquidation cascades, regulatory news) can cause spreads to behave unpredictably. Always maintain sufficient margin on both exchanges and never risk more than you can afford to lose.
Real incident patterns worth memorizing. Flash crash: a 10% wick on BTC triggers cross-exchange spread blowouts that look like opportunities but liquidate undermargined legs before they close. Exchange hack or freeze: withdrawals halt, your hedge is stranded — happened to FTX (2022), Bitfinex (2016), Mt. Gox (2014). Stablecoin depeg: USDT or USDC trading at $0.95 turns every quote-asset balance into a 5% loss; the May 2022 UST collapse cascaded across all perps. MEV-style frontrunning is a DEX concern when bridging assets. Fat-finger errors: an extra zero in order size has ended more careers than any market move. Network attacks on exchanges (BGP hijacks, regional ISP outages) can isolate your trade worker mid-cycle — Arbitron's heartbeat detects this within seconds but the position may still be open until connectivity returns.
Margin and Liquidation
Arbitron uses cross-margin mode by default on every exchange. Cross-margin pools your entire futures balance as collateral for all positions, which is the right choice for arbitrage: a temporary spread inversion on one leg can be offset by available margin from the rest of the wallet, preventing premature liquidation. Isolated margin, by contrast, allocates a fixed amount per position — protective for directional bets but actively harmful for arbitrage, where one leg's mark-to-market loss is structurally hedged by the other leg's gain. Under isolated mode the losing leg can liquidate while the winning leg sits with unrealized profit, breaking the hedge entirely. Cross-margin lets the structural hedge work as designed.
A concrete liquidation example. You hold a $10,000 long SOL-USDT perp at $150 with 10x leverage, posting $1,000 initial margin. Maintenance margin is typically 0.5% of notional = $50. Liquidation price ≈ entry × (1 − (initial − maintenance) / notional) = 150 × (1 − 950/10000) = $135.75. A 9.5% adverse move wipes you out. At 5x leverage the same math yields liquidation near $122 — a 19% buffer. For arbitrage, the hedged short leg on the other exchange offsets most of this risk, but only if cross-margin keeps both wallets funded. The lesson: leverage does not magnify arbitrage profit (the edge is the spread, not directional movement), so 3–5x is plenty and 20x+ is reckless.
Maintenance margin buffer rules: keep at least 30–50% free margin above maintenance on every exchange at all times. If your account equity is $1,000 and total maintenance margin requirement is $200, do not let free margin drop below ~$300. Monitor the Wallet panel — it shows used margin vs available margin per exchange. Top up immediately if any account dips below the 30% buffer. Funding rates can also bleed margin: a -0.1% funding charge every 8 hours on a $10,000 position equals $30 daily out of your wallet. On smaller exchanges (BloFin, Phemex), maintenance margin tiers step up sharply above $50k notional — verify the tier table before scaling position size.