Cross-Exchange Arbitrage Bot in Python

Arbitrage is the closest thing to a free lunch in trading. When the same asset trades at different prices on two exchanges, you buy on the cheaper and sell on the more expensive, capturing a risk-free spread. In practice, execution risk and fees erode the edge, but a well-designed python crypto trading bot can still find consistent opportunities.

Detecting Spreads

import ccxt\nbinance = ccxt.binance()\nkraken = ccxt.kraken()\nbtc_binance = binance.fetch_ticker("BTC/USDT")["ask"]\nbtc_kraken = kraken.fetch_ticker("XBT/USD")["bid"]\nspread = btc_kraken - btc_binance\nif spread > threshold:\n    print(f"Arb opportunity: {spread}")

Execution Challenges

The three biggest risks in automated crypto trading arbitrage are: execution lag (the spread closes before you fill both sides), transfer delay (moving funds between exchanges takes time), and fee erosion (taker fees on both sides eat the profit). Design your bot to account for all three.

Capital Efficiency

Keep pre-funded balances on both exchanges to eliminate transfer delay. Calculate the minimum profitable spread as: Min Spread = Fee A + Fee B + Slippage A + Slippage B. Only execute when the observed spread exceeds this hurdle.