Basis trading spot-futures algorithm development

Development of Basis Trading Algorithm (Spot-Futures)

Basis trading — one of few DeFi strategies with predictable income source. Buy ETH spot, simultaneously short ETH perpetual futures on same volume. Delta-neutral position. Funding rate on perpetual — your income. When market bullish, longs pay shorts. In 2021-2023 this yielded 20-60% APY with no directional risk.

Sounds simple. But implementation that works without losses on sharp market moves, negative funding, and margin calls — this is engineering task.

Risk sources breaking simple implementations

Funding rate reverses

Funding rate on Binance Perp, dYdX, GMX, Hyperliquid — variable. On bullish market longs pay shorts (positive funding, you receive). On bearish — opposite (negative funding, you pay). If your algorithm can't exit position on regime change, negative funding will eat your capital.

Implementation: threshold on negative funding rate. If 8-hour funding goes below -0.01% three periods straight — algorithm begins position closure. Not instant (to not move market), but TWAP exit over several hours.

Liquidation of short position on pump

Delta-neutrality — mantra breaking on extreme moves. ETH up 30% per hour. Your short on perpetual loses margin faster than you can top up. If margin ratio falls below liquidation threshold — position forcibly closes. Spot remains. You go from delta-neutral to delta-long with liquidation loss (usually 0.5-1% of position as liquidation fee).

Solution — margin buffer. Keep perpetual margin ratio not at liquidation threshold, but with 2-3x buffer. On pump — auto-top-up margin from spot wallet or close part of spot position. Algorithm tracks unrealizedPnl and marginRatio in real-time and acts before exchange force-liquidates.

Roll management on dated futures

If using dated futures (not perpetuals), position expires. 3-7 days before expiry need "roll": close current contract and open next. Price difference between them — roll yield (can be positive or negative).

Automatic roller requires: monitoring time to expiry, calculating roll cost, executing two orders atomically (or as close as possible). On CEX this is relative order: sell current and buy next via calendar spread order if exchange supports (Binance, CME crypto). If not — risk of slippage between two separate orders.

Building algorithm

Choosing venues

For pure DeFi approach: spot on Uniswap V3, short on dYdX v4 or Hyperliquid. For maximum liquidity and stability — Binance spot + Binance Perp (CEX risk, but minimal slippage).

Calculating funding PnL

# Funding per period = notional * funding_rate
# funding_rate at most exchanges — 8-hourly
funding_8h = position_size_usd * funding_rate_current
annualized_apy = funding_8h * 3 * 365  # 3 periods per day, 365 days

# Net APY accounting for roll and fees
net_apy = annualized_apy - entry_exit_fees - borrow_cost - roll_cost

Algorithm calculates net_apy for each potential position and enters only above threshold (e.g., 15% APY after all costs).

Execution engine

Opening position — not one order. Coordinated action:

1. Check available liquidity on perpetual (bid/ask spread < threshold)
2. Place limit order on spot (or market with minimal slippage)
3. Immediately after spot executes — place short on perpetual on same volume
4. If perpetual doesn't execute in N seconds — close spot, start over

Discrepancy between spot and perpetual execution creates temporary directional risk. On liquid pairs (BTC, ETH) — milliseconds. On less liquid altcoins — seconds, and price difference can be significant.

Use WebSocket connections to exchanges for real-time fills. REST API for order submission too slow on active market.

Position monitoring

Critical metrics to track in real-time:

• delta = spot position + perpetual position (should be ~0)
• margin_ratio perpetual (alert near 150% of liquidation threshold)
• funding_rate current and 7-day moving average
• funding_received_cumulative vs fees_paid_cumulative — actual PnL

PostgreSQL for history. TimescaleDB for time-series (funding rates, prices). Grafana for dashboard. PagerDuty or Telegram for alerts on margin call approach.

Timeline estimates

Algorithm for one trading pair on two CEX (spot + perp) with basic monitoring — 1-1.5 weeks. With multi-pair, multi-exchange logic, automatic roll management and full risk management — 2-3 weeks. Integration with on-chain DEX perpetuals (dYdX, GMX) adds complexity — separate estimate. Cost calculated after clarifying exchange integrations and risk requirements.