A lightweight, high-performance backtesting library for trading strategy development and optimization. Built on Polars for fast vectorized data processing with an event-driven execution loop for flexible strategy logic.
- Hybrid architecture — vectorized preprocessing (Polars) + event-driven execution loop
- 25+ built-in indicators — SMA, EMA, RSI, MACD, Bollinger Bands, ATR, SuperTrend, ADX, and more
- Complete order system — market, limit, stop, stop-limit, bracket orders, day/GTC orders
- Risk management — stop-loss, take-profit, trailing stops, position size limits, drawdown stops
- Short selling — negative positions, borrow costs, position reversals
- Margin & leverage — configurable leverage, margin tracking, margin calls
- Commission models — percentage, fixed, maker/taker, volume-tiered, custom
- Position sizing — fixed, percent, fixed-risk, Kelly, volatility-based
- Weight-based backtesting — declarative portfolio allocation with
backtest_weights()orWeightStrategy, rebalance scheduling, stop-loss/take-profit, next-actions output - Multi-asset — pass a dict of DataFrames or a long-format DataFrame with
symbolcolumn; all OHLC data preserved - Dynamic universe —
UniverseProviderprotocol filters tradeable symbols per bar; built-inAgeFilter,VolumeFilter,TopN,CompositeFilter; token lifecycle tracking viactx.first_seen_bar/ctx.bar_count - Parallel optimization — grid search, multi-objective Pareto, Bayesian optimization
- Walk-forward analysis — rolling and anchored train/test splits
- Advanced analysis — Monte Carlo simulation, look-ahead bias detection, permutation testing
- Visualization — interactive Plotly charts (price, equity, drawdown, trade markers, heatmaps)
- AMM-aware execution — pluggable
SlippageModelwithFlatSlippageandAMMSlippage(constant-product formula) - Exchange rate support —
Engine(exchange_rate=...)converts equity curve to USD; reports dual quote/USD metrics - DeFi indicators —
buy_sell_ratio,net_flow,trade_intensity,pump_detector,rug_pull_detector, AMMprice_impact_estimate,liquidity_ratio, and more - Trade data pipeline — validate and aggregate raw DEX/AMM trades into OHLCV bars (time-based or trade-count), with buy/sell volume split, VWAP, and optional USD conversion
- Data utilities — validation, cleaning, OHLCV resampling
- Optional TA-Lib integration — wrap any TA-Lib function into Polars expressions
pip install polarbtOr with optional extras:
pip install polarbt[plotting] # Plotly charts
pip install polarbt[talib] # TA-Lib integrationInstall from source:
git clone git@github.com:nikkisora/PolarBT.git
cd PolarBT
pip install -e .import polars as pl
import yfinance as yf
from polarbt import Engine, Strategy
from polarbt import indicators as ind
from polarbt.core import BacktestContext
from polarbt.plotting import plot_backtest
class SMACross(Strategy):
def preprocess(self, df: pl.DataFrame) -> pl.DataFrame:
return df.with_columns(
ind.sma("close", 10).alias("sma_fast"),
ind.sma("close", 30).alias("sma_slow"),
).with_columns(
ind.crossover("sma_fast", "sma_slow").alias("buy"),
ind.crossunder("sma_fast", "sma_slow").alias("sell"),
)
def next(self, ctx: BacktestContext) -> None:
if ctx.row.get("buy"):
ctx.portfolio.order_target_percent("asset", 1.0)
elif ctx.row.get("sell"):
ctx.portfolio.close_position("asset")
# Download data from Yahoo Finance
ticker = yf.download("AAPL", start="2016-01-01", end="2026-01-01", auto_adjust=True)
ticker = ticker.droplevel("Ticker", axis=1).reset_index()
data = pl.from_pandas(ticker)
# Run backtest
engine = Engine(SMACross(), data, commission=.005, initial_cash=100_000)
results = engine.run()
print(results)
# Interactive chart saved to HTML
fig = plot_backtest(engine, title="SMA Crossover — AAPL", indicators=["sma_fast", "sma_slow"])
fig.write_html("backtest.html")Equity Final [$] 366,236.83
Equity Peak [$] 433,930.72
Return [%] 266.24
Buy & Hold Return [%] 1044.52
Return (Ann.) [%] 14.08
CAGR [%] 14.08
Volatility (Ann.) [%] 19.78
Sharpe Ratio 0.76
Sortino Ratio 0.92
Calmar Ratio 0.44
Max. Drawdown [%] -32.16
Avg. Drawdown Duration [bars] 38
Max. Drawdown Duration [bars] 730
# Trades 42
Win Rate [%] 47.62
Best Trade [%] 57.11
Worst Trade [%] -13.43
Avg. Trade [%] 3.94
Max. Trade Duration [bars] 128
Avg. Trade Duration [bars] 39
Avg. Trade MDD [%] -8.78
Profit Factor 1.79
Expectancy [$] 6338.97
SQN 1.27
Kelly Criterion 0.2098
For portfolio allocation strategies, skip the event loop entirely — just supply target weights per (date, symbol):
import polars as pl
from polarbt import backtest_weights
# data: long-format DataFrame with columns date, symbol, close, weight
result = backtest_weights(
data,
resample="M", # rebalance monthly
resample_offset="2d", # delay 2 trading days after month boundary
fee_ratio=0.001,
stop_loss=0.10, # 10% per-position stop-loss
position_limit=0.5, # max 50% in any single name
initial_capital=100_000,
)
print(result.metrics) # standard BacktestMetrics
print(result.trades.head()) # per-trade log
print(result.next_actions) # forward-looking rebalance actionsPolarBT can ingest raw DEX/AMM trade data (e.g. Pump.fun on Solana), aggregate it into OHLCV bars, apply DeFi-specific indicators, and backtest with AMM-aware slippage — all in a single pipeline.
import polars as pl
from polarbt import Engine, Strategy, indicators_defi as defi
from polarbt.core import BacktestContext
from polarbt.data.trades import aggregate_trades, validate_trades
from polarbt.slippage import AMMSlippage
from polarbt.universe import AgeFilter, CompositeFilter, VolumeFilter
# 1. Load and validate raw trades
trades = pl.read_parquet("trades.parquet")
assert validate_trades(trades.sort("symbol", "timestamp")).valid
# 2. Aggregate to 5-minute OHLCV bars
bars = aggregate_trades(trades.sort("symbol", "timestamp"), "5m", min_trades=3)
# 3. Define a strategy using DeFi indicators
class PumpMomentum(Strategy):
def preprocess(self, df: pl.DataFrame) -> pl.DataFrame:
return df.with_columns(
defi.buy_sell_ratio().over("symbol").alias("bs_ratio"),
defi.trade_intensity(window=10).over("symbol").alias("intensity"),
)
def next(self, ctx: BacktestContext) -> None:
for sym in ctx.symbols:
row = ctx.row(sym)
if row.get("bs_ratio", 0) > 0.7 and row.get("intensity", 0) > 2.0:
ctx.portfolio.order_target_percent(sym, 0.1)
elif row.get("bs_ratio", 0) < 0.3:
ctx.portfolio.close_position(sym)
# 4. Run with AMM slippage and universe filtering
engine = Engine(
PumpMomentum(),
bars,
initial_cash=100.0, # in SOL
commission=0.01,
slippage=AMMSlippage(), # uses pool_reserve_last from bar data
universe_provider=CompositeFilter(AgeFilter(min_bars=5), VolumeFilter(min_volume=1.0)),
)
results = engine.run()
print(results)| Example | Description |
|---|---|
example.py |
Basic SMA crossover |
example_sma_crossover_stoploss.py |
SMA crossover with ATR stop-loss and trailing stop |
example_rsi_bracket_orders.py |
RSI mean reversion with bracket orders |
example_momentum_rotation.py |
Multi-asset momentum rotation |
example_ml_strategy.py |
ML model integration |
example_walk_forward.py |
Walk-forward analysis workflow |
example_advanced_analysis.py |
Full workflow: optimization, heatmaps, Monte Carlo, permutation test |
example_limit_orders.py |
Limit orders and stop-loss |
example_trade_analysis.py |
Trade-level analysis |
example_plotting.py |
Interactive chart generation |
example_commission.py |
Commission model comparison |
example_multi_asset.py |
Multi-asset dict input |
example_weight_backtest.py |
Weight-based portfolio backtest |
example_defi_trades.py |
DeFi trade data pipeline with AMM slippage |

