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name: crypto-pair-fee-optimization description: "Analysis of crypto-to-crypto vs crypto-to-fiat (USD) trading on Alpaca for fee optimization and risk considerations" author: Claude Code date: 2026-01-01

Crypto Pair Fee Optimization - Research Notes

Experiment Overview

Context

When rebalancing crypto portfolios or rotating between assets, there are two approaches:

1. Crypto-to-USD route: Sell asset A for USD, buy asset B with USD (2 trades)
2. Crypto-to-crypto route: Trade asset A directly for asset B (1 trade)

The question: Does Alpaca's fee structure favor one approach over the other?

Key Finding: Fee Structure is Identical

Per docs/rules_and_fees/AlpacaCryptoLLCFeeDisclosure.pdf, Alpaca uses the same maker/taker fees regardless of pair type:

No per-trade fee advantage exists between pair types.

Verified Advantage: Trade Count Reduction

The only fee advantage comes from reducing the number of trades:

Copy# Fee calculation for portfolio rotation
def calculate_rotation_fees(num_assets: int, fee_rate: float = 0.0025) -> dict:
    """Compare fees for crypto rotation strategies."""
    # Via USD: sell all to USD, buy new positions
    usd_route_trades = num_assets * 2  # sell + buy for each
    usd_route_fee = usd_route_trades * fee_rate

    # Via crypto pairs: direct swaps where available
    crypto_route_trades = num_assets  # direct swaps
    crypto_route_fee = crypto_route_trades * fee_rate

    return {
        'usd_route_trades': usd_route_trades,
        'usd_route_fee_pct': usd_route_fee * 100,
        'crypto_route_trades': crypto_route_trades,
        'crypto_route_fee_pct': crypto_route_fee * 100,
        'savings_pct': (1 - crypto_route_fee / usd_route_fee) * 100
    }

When Crypto-to-Crypto is Advantageous

1. Portfolio rebalancing - Rotating between crypto assets you intend to hold
2. Stablecoin parking - Using USDC/USDT pairs to avoid USD conversion delays
3. Tax strategy - Potentially avoiding USD realization events (jurisdiction-dependent, consult tax advisor)

When Crypto-to-USD is Better

1. Profit realization - Converting to USD for withdrawal/spending
2. Risk-off moves - USD doesn't fluctuate while waiting to re-enter
3. Simpler accounting - USD basis is clearer for tax reporting
4. Wider liquidity - USD pairs typically have tighter spreads

Failed Attempts (Critical)

Risk Considerations

Copy# Risk factors for crypto-to-crypto pairs
double_volatility_exposure: true  # Both sides of trade can move
liquidity_variance: "USD pairs typically deeper"
spread_risk: "Exotic pairs may have wider spreads"
implementation_complexity: "Requires broker/backtest updates"

Available Alpaca Crypto Pairs

Copy# Base currencies for crypto-to-crypto
BTC_pairs: [BCH, ETH, LTC, UNI]
USDT_pairs: [AAVE, BCH, BTC, DOGE, ETH, LINK, LTC, SUSHI, UNI, YFI]
USDC_pairs: [AAVE, AVAX, BAT, BCH, BTC, CRV, DOGE, DOT, ETH, GRT, LINK, LTC, SHIB, SKY, SUSHI, UNI, XTZ, YFI]
USD_pairs: "20+ assets including all USDC/USDT options plus XRP"

Implementation Notes

Current codebase trades crypto/USD only (e.g., BTC/USD). To implement crypto-to-crypto:

1. Update alpaca_trading/trading/broker.py to handle non-USD quote currencies
2. Modify backtest infrastructure for multi-base accounting
3. Add fee calculation that tracks the "credited side" denomination
4. Consider liquidity/spread modeling for exotic pairs

Key Insights

• Fee percentages are identical across all pair types on Alpaca
• The only fee advantage is reducing trade count (50% savings on rotations)
• Crypto-to-crypto exposes you to volatility on both sides of the trade
• Stablecoin pairs (USDC/USDT) offer a middle ground: crypto liquidity with USD-like stability
• Implementation requires non-trivial changes to broker and backtest systems

References

• docs/rules_and_fees/AlpacaCryptoLLCFeeDisclosure.pdf (local)
• Alpaca Crypto Fees Documentation
• Alpaca Crypto Coin Pair FAQ
• Alpaca Crypto Trading Documentation