Global Low-CAPE Value Strategy with Annual Rebalance

Log in to collect

Onsite backtest IDE

Quant Buffet native backtest IDE

Edit and run Quant Buffet Python for Global Low-CAPE Value Strategy with Annual Rebalance 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 →

Ready — edit code, then Run backtest.
IDE · 42 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
5.73%
Sharpe
0.35
Max DD
-66.92%
Vol
24.66%
Sortino
0.54
Beta
0.91
Up days
79%

Showing saved draft baseline until you re-run.

Equity curve (indexed = 100)

Accent = strategy · dashed grey = buy-and-hold benchmark

2000-072026-0782259
Drawdown
Worst -55.6%-56%
Metrics bar chart
CAGRSharpeSortinoVol|DD|Up%Grey = baseline · Accent = live run
Monthly returns
2021-102026-07 · last 24 months

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: Momentum rotationAssets: SPY, TLT, GLD, BIL
# Generated from Quant Buffet → QuantConnect LEAN
# Strategy: Global Low-CAPE Value Strategy with Annual Rebalance
# Detected pattern: Momentum rotation
# 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: Hold top 3 by 126-day return; monthly.

    def Rebalance(self):
        scores = {}
        for symbol in self.symbols:
            hist = self.History(symbol, 126 + 5, Resolution.Daily)
            if hist.empty: continue
            close = hist["close"]
            if hasattr(close, "unstack"):
                close = close.unstack(level=0).iloc[:, 0]
            if len(close) < 126 + 1: continue
            scores[symbol] = float(close.iloc[-1] / close.iloc[-126 - 1] - 1)
        ranked = sorted(scores.items(), key=lambda kv: kv[1], reverse=True)[:3]
        for symbol in self.symbols:
            self.SetHoldings(symbol, 0)
        if ranked:
            w = 1.0 / len(ranked)
            for symbol, _ in ranked:
                self.SetHoldings(symbol, w)

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

Screenshot from the original paper

Screenshot from the original paper
Screenshot from the original paper

Strategy in a nutshell

The investment universe consists of 32 countries with easily accessible equity markets (via ETFs, for example). At the end of every year, the investor calculates Shiller’s “CAPE” Cyclically Adjusted PE) ratio, for each country in his investment universe. CAPE is the ratio of the real price of the equity market (adjusted for inflation) to the 10-year average of the country’s equity index (again adjusted for inflation). The whole methodology is explained well on Shiller’s home page (http://www.econ.yale.edu/~shiller/data.htm) or http://turnkeyanalyst.com/2011/10/the-shiller-pe-ratio/). The investor then invests in the cheapest 33% of countries from his sample if those countries have a CAPE below 15. The portfolio is equally weighted (the investor holds 0% cash instead of countries with a CAPE higher than 15) and rebalanced yearly.

Economic rationale

The anomaly has its source in investor psychology. Academic research postulates that investors overreact to news and events; “winners”, i.e. favourite countries, tend to be overvalued while “losers”, i.e. neglected countries, are undervalued. The contrarian investor can, therefore, exploit this generic investor mentality to capitalize on the inefficiency of the market to reap financial gains when stock prices revert to their intrinsic values.

Backtest performance

Annualised return5.73%
Volatility24.66%
Beta0.91
Sharpe ratio0.35
Sortino ratio0.54
Maximum drawdown-66.92%
Win rate79%