Debt-Equity Spread in Bonds
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Quant Buffet native backtest IDEEdit and run Quant Buffet Python for Debt-Equity Spread in Bonds 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: Debt-Equity Spread in Bonds
# Detected pattern: Custom / hybrid
# 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: Custom Quant Buffet logic — adapt the signal block to match your lab on_day().
def Rebalance(self):
# Pattern: custom — Custom Quant Buffet logic — adapt the signal block to match your lab on_day().
# 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
Hui Chen; Zhiyao Chen; Jun Li
- Massachusetts Institute of Technology
- National Bureau of Economic Research
- ?National Bureau of Economic Research (NBER)
- Chinese University of Hong Kong
- ?The Chinese University of Hong Kong (CUHK) - Department of Finance
- ?University of Texas at Dallas
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3944082


Strategy in a nutshell
This strategy trades corporate bonds of non-financial firms listed on NYSE, AMEX, and NASDAQ. Using CRSP and Compustat for equity and accounting data, and Lehman Brothers Fixed Income Database, NAIC, and WRDS for bond data, the debt-equity spread is calculated as the difference between the actual credit spread and the equity-implied credit spread. The latter is derived from theoretical bond prices and matched Treasury yields. Each month, bonds are sorted into quintiles by their firm’s debt-equity spread. The portfolio goes long the highest quintile and short the lowest, with monthly rebalancing and value-weighted positions.
Economic rationale
The debt-equity spread identifies relative mispricing between bonds and equities. A high spread signals overvalued equity and undervalued bonds, while a low spread indicates the opposite. This anomaly persists as firms and insiders exploit mispricing via equity issuance and debt retirement, and executives tend to sell overvalued stock. The effect is robust to standard risk factors, firm characteristics, and demonstrates systematic, persistent mispricing exploitable through this strategy.