Conditional FX Correlation Risk

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Edit and run Quant Buffet Python for Conditional FX Correlation Risk 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
3.30%
Sharpe
0.27
Max DD
-51.95%
Vol
18.24%
Sortino
0.42
Beta
0.26
Up days
66%

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: Momentum rotationAssets: SPY, TLT, GLD, BIL
# Generated from Quant Buffet → QuantConnect LEAN
# Strategy: Conditional FX Correlation Risk
# 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 1 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)[:1]
        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

Dynamic Allocations for Currency Investment Strategies

AuthorsKei Nakagawa; Ryuta Sakemoto

Institute
  • JPNomura Holdings (Japan)
  • ?Nomura Asset Mamagement Co,Ltd
  • JPOkayama University
  • JPKeio University

Screenshot from the original paper

Screenshot from the original paper
Screenshot from the original paper

Strategy in a nutshell

The dataset consists of daily spot and one-month forward exchange rates sourced from Datastream, analyzed from the perspective of a U.S. investor with the U.S. dollar as the base currency. Conditional correlations between FX spot rate changes are estimated over rolling three-month windows across nine FX pairs, generating 36 correlation measures.

At each month-end, the correlations are ranked into deciles, and the cross-sectional dispersion of conditional FX correlations (FXC) is calculated as the difference between the top and bottom deciles. The innovation in FXC (ΔFXC) is then extracted. Currency pairs are sorted based on their factor betas with respect to ΔFXC, and three portfolios are constructed: long in low-beta currencies, short in high-beta currencies, with the intermediate group excluded.

Currency excess returns are measured using forward premiums: for long positions, as the difference between the bid price of the one-month forward and the spot ask price (scaled by the ask); and for short positions, as the difference between the spot bid and the one-month forward ask (scaled by the bid). The total portfolio excess return equals the sum of long and short position excess returns.

Economic rationale

The strategy builds on Mueller et al. (2017), who show that FX correlations become more dispersed during periods of financial stress: high-correlation pairs become even more correlated, while low-correlation pairs diverge. This widening of the cross-section creates priced risk exposure.

Currencies that serve as hedges in stressful periods (high-beta pairs with respect to ΔFXC) deliver lower average returns in normal times, while currencies that perform poorly in stress (low-beta pairs) deliver higher average returns. The negative relation between ΔFXC betas and excess returns supports the presence of a priced FX correlation risk factor. Thus, the strategy profits from systematically exploiting this risk premium embedded in cross-sectional FX correlation dynamics.

Backtest performance

Annualised return3.30%
Volatility18.24%
Beta0.26
Sharpe ratio0.27
Sortino ratio0.42
Maximum drawdown-51.95%
Win rate66%