US Momentum Strategy Using 12-Month Returns Excluding Most Recent Month

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Edit and run Quant Buffet Python for US Momentum Strategy Using 12-Month Returns Excluding Most Recent Month 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 · 36 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
6.00%
Sharpe
0.63
Max DD
-18.15%
Vol
10.11%
Sortino
0.93
Beta
0.35
Up days
50%

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: Absolute momentumAssets: SPY, TLT, GLD, BIL
# Generated from Quant Buffet → QuantConnect LEAN
# Strategy: US Momentum Strategy Using 12-Month Returns Excluding Most Recent Month
# Detected pattern: Absolute momentum
# 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 with positive 252-day return; equal-weight; monthly.

    def Rebalance(self):
        # Pattern: abs_momentum — Long assets with positive 252-day return; equal-weight; monthly.
        # Default: equal-weight. Port your make_on_day weights here via SetHoldings.
        w = 1.0 / len(self.symbols) if self.symbols else 0.0
        for symbol in self.symbols:
            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

Fact, Fiction and Momentum Investing

AuthorsClifford S. Asness; Andrea Frazzini; Ronen Israel; Tobias J. Moskowitz

Institute
  • Capital University
  • ?AQR Capital Management, LLC
  • ATAgency for Quality Assurance and Accreditation Austria
  • Yale University
  • National Bureau of Economic Research
  • ?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 scope includes stocks from the NYSE, AMEX, and NASDAQ. Momentum is determined by the returns from the past 12 months, omitting the latest month to dodge biases related to microstructure and liquidity. To leverage this "momentum," the UMD portfolio adopts a strategy where it goes long on stocks demonstrating high returns over the previous year and shorts those with low returns, aiming to capitalize on the tendency of stocks to continue moving in their recent directional trend. This approach seeks to maximize gains from stocks on an upward trajectory while minimizing exposure to those declining.

Economic rationale

Academic research robustly supports the momentum effect, largely attributed to behavioral biases such as investor herding, overreaction, underreaction, and confirmation bias. For instance, profit can result from buying stocks post-initial positive news, leveraging the market's delayed full response. Rachwalski and Wen suggest in “Momentum, Risk and Underreaction” that momentum profits arise from risks overlooked by standard models and underreaction to new risk information. Long-term momentum strategies, associated with higher risks, yield greater returns compared to short-term strategies. Additionally, momentum investing has been shown to be tax-efficient, as highlighted by Israel and Moskowitz in “How Tax Efficient are Equity Styles?”. They found that after-tax, value and momentum strategies outperform, with momentum being surprisingly tax-efficient despite its higher turnover. This efficiency comes from generating significant short-term losses and lower dividend income, allowing for substantial tax optimization without deviating from the momentum style.

Backtest performance

Annualised return6.00%
Volatility10.11%
Beta0.35
Sharpe ratio0.63
Sortino ratio0.93
Maximum drawdown-18.15%
Win rate50%