NautilusTrader vs Backtesting.py (2026)
NautilusTrader (open-source event-driven trading engine with a rust core, a python api, and true backtest-live parity) and Backtesting.py (lightweight open-source python library for backtesting single-instrument strategies) solve backtesting differently. The table below compares them on verified specs and pricing; full details are in each review.
Side by side
| NautilusTrader | Backtesting.py | |
|---|---|---|
| Overall score | 7.9 / 10 | 7.1 / 10 |
| Engine type | event-driven | hybrid |
| Pricing model | open-source | open-source |
| Free tier | Yes | Yes |
| Entry price | $0 | $0 |
| Languages | Python (3.12-3.14 API), Rust (core engine) | Python |
| Asset classes | Equities, Futures, Options, FX, Crypto (spot and perpetuals), Betting markets (Betfair), Prediction markets (Polymarket) | stocks, forex, crypto, futures, any instrument with OHLC(V) candlestick data |
| Bundled data | None: bring your own data. First-party adapters cover Databento (equities/futures/options ticks) and Tardis (crypto L2/L3), and a Parquet-based data catalog handles custom data. | None beyond bundled sample datasets (GOOG daily, EURUSD intraday) used in tutorials. You bring your own OHLCV data as pandas DataFrames from yfinance, ccxt, broker APIs, or paid vendors |
| Finest resolution | Nanosecond (tick, trade, and order-book events) | Any OHLC bar interval you supply, including sub-minute bars; raw tick or order-book data must be resampled to candles first |
| Live trading | Yes | No |
| Options support | Yes | No |
| Open source | Yes | Yes |
NautilusTrader
Open-source event-driven trading engine with a Rust core, a Python API, and true backtest-live parity
Backtesting.py
Lightweight open-source Python library for backtesting single-instrument strategies
Frequently asked questions
Is NautilusTrader better than Backtesting.py?+
They target different users. NautilusTrader: experienced python developers and quants who want institutional-grade, tick-level backtests that deploy unchanged to live trading. multi-venue crypto and event-driven strategies are the sweet spot. Backtesting.py: beginner-to-intermediate python traders who want the fastest path from strategy idea to a credible single-instrument backtest with interactive charts, without paying anything or learning a heavyweight framework. Our scores: NautilusTrader 7.9/10, Backtesting.py 7.1/10.
Which is cheaper, NautilusTrader or Backtesting.py?+
NautilusTrader entry pricing: $0 (open-source). Backtesting.py: $0 (open-source). See each review for full verified pricing tables.
Educational content only, not investment advice. Specs and prices come from each platform's official pages; see the individual reviews for sources and last-verified dates.