Momentum and Asset Growth Long-Short Strategy with January Exclusion
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Quant Buffet native backtest IDEEdit and run Quant Buffet Python for Momentum and Asset Growth Long-Short Strategy with January Exclusion 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 →
Quant Buffet syntax cheat sheet (copy / insert)
Paste these fragments into the editor. The sandbox rejects QuantConnect, os, and network libraries.
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_metricsASSETS = ["SPY", "QQQ", "TLT", "GLD", "BIL"]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, readyengine.set_target_weights(dt, {"SPY": 0.60, "BIL": 0.40})Live backtest performance
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.
# Generated from Quant Buffet → QuantConnect LEAN
# Strategy: Momentum and Asset Growth Long-Short Strategy with January Exclusion
# 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
Strategy in a nutshell
The investment universe consists of NYSE, AMEX, and NASDAQ stocks (data for the backtest in the
Economic rationale
Academic research shows that the existing literature does not offer clear answers as to why firm investment, measured by asset growth, should be connected to return continuation. However, results from this academic study are highly statistically significant and based on a long data sample. The interaction between asset growth and momentum survives the inclusion of the number of control variables. Confidence in this combined strategy, therefore, could be high.
III. SOURCE PAPER
Firm Expansion and Stock Price Momentum [Click to Open PDF]
Peter M. Nyberg, Aalto University ; Salla Pöyry, Hanken School of Economics
We document a significant and robust connection between firm-level asset changes and return momentum. Momentum profits are large and significant for firms that have experienced large asset expansions or contractions, whereas they otherwise are small and often insignificant. The interaction pattern is not subsumed by previously documented drivers of momentum and shows up in market states where prior literature has documented an absence of momentum profits. Furthermore, we find a positive time-series relationship between aggregate asset growth and return momentum, and the effect of aggregate asset growth is stronger than that of variables related to business cycles and investor sentiment. While most existing models of firm investment and momentum cannot explain our results, recent real options models appear to hold the most promise.