US Equity Value Factor Strategy: Monthly Long High and Short Low Book-to-Price Stocks

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Edit and run Quant Buffet Python for US Equity Value Factor Strategy: Monthly Long High and Short Low Book-to-Price Stocks in the browser. Results update live with equity, drawdown, and metrics charts. Allowed: backtest.data, backtest.engine, backtest.metrics, numpy, pandas. Define ASSETS and make_on_day(prices). Shortcut: Ctrl+Enter. API docs →

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IDE · 40 lines
Quant Buffet syntax cheat sheet (copy / insert)

Paste these fragments into the editor. The sandbox rejects QuantConnect, os, and network libraries.

Required imports
Only these libraries are allowed in the sandbox.
from __future__ import annotations

import numpy as np
import pandas as pd

from backtest.data import load_daily_prices
from backtest.engine import EngineConfig, PortfolioEngine
from backtest.metrics import compute_metrics
ASSETS list (whitelisted ETFs)
Module-level list. Tickers must be in the Quant Buffet whitelist.
ASSETS = ["SPY", "QQQ", "TLT", "GLD", "BIL"]
make_on_day contract
Must return (on_day, ready). on_day calls engine.set_target_weights.
def make_on_day(prices: pd.DataFrame):
    cols = [c for c in ASSETS if c in prices.columns]
    sma = prices[cols].rolling(200, min_periods=200).mean()
    state = {"last": None}

    def on_day(engine: PortfolioEngine, dt: pd.Timestamp) -> None:
        if sma.loc[dt].isna().all():
            return
        key = (dt.year, dt.month)
        if state["last"] == key:
            return
        state["last"] = key
        long = [
            s for s in cols
            if pd.notna(prices.at[dt, s]) and pd.notna(sma.at[dt, s])
            and prices.at[dt, s] > sma.at[dt, s]
        ]
        weights = {} if not long else {s: 1.0 / len(long) for s in long}
        engine.set_target_weights(dt, weights)

    ready = sma.dropna(how="all").index.min() if sma.notna().any().any() else None
    return on_day, ready
Set target weights
Weights should sum to about 1.0. Empty dict = 100% cash.
engine.set_target_weights(dt, {"SPY": 0.60, "BIL": 0.40})

Live backtest performance

CAGR
6.77%
Sharpe
0.74
Max DD
-19.09%
Vol
9.43%
Sortino
1.11
Beta
0.28
Up days
53%

Run the backtest to populate charts.

Export to your platform

Transform Quant Buffet lab code (ASSETS + make_on_day / PortfolioEngine) into native classes for a third-party IDE — then copy and paste.

Run in: QuantConnect Cloud or LEAN CLI · QCAlgorithm with Equity securities and monthly rebalance.

Detected pattern: SMA trendAssets: SPY, TLT, GLD, BIL
# Generated from Quant Buffet → QuantConnect LEAN
# Strategy: US Equity Value Factor Strategy: Monthly Long High and Short Low Book-to-Price Stocks
# Detected pattern: SMA trend
# Source uses Quant Buffet lab APIs (ASSETS + make_on_day / PortfolioEngine).
# Review fees, data, and risk before live trading — educational export only.

from AlgorithmImports import *


class QuantBuffetExport(QCAlgorithm):
    def Initialize(self):
        self.SetStartDate(2010, 1, 1)
        self.SetCash(100000)
        tickers = ["SPY", "TLT", "GLD", "BIL"]
        self.symbols = []
        for t in tickers:
            if "-" in t:  # crypto proxy e.g. BTC-USD
                self.symbols.append(self.AddCrypto(t.replace("-USD", ""), Resolution.Daily).Symbol)
            else:
                self.symbols.append(self.AddEquity(t, Resolution.Daily).Symbol)
        self.Schedule.On(
            self.DateRules.MonthStart(self.symbols[0]),
            self.TimeRules.AfterMarketOpen(self.symbols[0], 30),
            self.Rebalance,
        )
        # Logic: Long assets where close > SMA(200); equal-weight; monthly.

    def Rebalance(self):
        longs = []
        for symbol in self.symbols:
            hist = self.History(symbol, 200 + 5, Resolution.Daily)
            if hist.empty: continue
            close = hist["close"].unstack(level=0).iloc[:, 0] if hasattr(hist["close"], "unstack") else hist["close"]
            if len(close) < 200: continue
            if float(close.iloc[-1]) > float(close.iloc[-200:].mean()):
                longs.append(symbol)
        weight = 1.0 / len(longs) if longs else 0.0
        for symbol in self.symbols:
            self.SetHoldings(symbol, weight if symbol in longs else 0.0)

Exported code uses the platform’s native classes and libraries. Install dependencies in your third-party IDE, then run. Validate before live trading.

Academic paper

Fact, Fiction, and the Size Effect

AuthorsRon Alquist; Ronen Israel; Tobias J. Moskowitz

Institute
  • United States Department of the Treasury
  • ?Financial Stability Oversight Council, U.S. Treasury
  • Capital University
  • ?AQR Capital Management, LLC
  • National Bureau of Economic Research
  • ATAgency for Quality Assurance and Accreditation Austria
  • Yale University
  • ?AQR Capital
  • ?National Bureau of Economic Research (NBER)
  • ?Yale University, Yale SOM

Screenshot from the original paper

Screenshot from the original paper

Strategy in a nutshell

The investment universe encompasses NYSE, AMEX, and NASDAQ stocks, targeting "value" investing through the HML portfolio, which longs stocks with high book-to-price ratios and shorts those with low ratios. This approach includes analyzing the average returns of two subsets: HML small, focusing on small-cap stocks, and HML large, targeting large-cap stocks, both adopting a value investing stance. The portfolio, equally weighted across all holdings, undergoes monthly rebalancing to maintain its strategy alignment and capture the essence of value investing through a diversified approach across market capitalizations.

Economic rationale

One theory suggests investors excessively favor growth stocks due to their growth potential, leading to value stocks being undervalued. Some scholars argue that the market value to book value ratio acts as a risk indicator, positing that the higher returns from low MV/BV stocks serve as a reward for bearing additional risk. Typically, stocks with low MV/BV ratios are in financial distress, further reinforcing the concept that their higher returns compensate investors for the increased risk associated with these stocks.

Backtest performance

Annualised return6.77%
Volatility9.43%
Beta0.28
Sharpe ratio0.74
Sortino ratio1.11
Maximum drawdown-19.09%
Win rate53%