The Mathematics of Pearson Correlation in Currency Portfolios
Holding simultaneous long positions on EUR/USD and GBP/USD does not represent diversification—it concentrates your portfolio into a double short-dollar trade. The Pearson correlation coefficient measures linear co-movement between asset returns on a scale from -1.00 (perfect inverse relationship) to +1.00 (perfect direct co-movement):
# Pearson Correlation Formula
r_xy = Covariance(X, Y) / (StdDev(X) * StdDev(Y))
Current Major Institutional Correlation Heat Map (Rolling 90-Day Matrix)
| Pair | EUR/USD | GBP/USD | USD/CHF | USD/JPY | XAU/USD (Gold) |
|---|---|---|---|---|---|
| EUR/USD | +1.00 | +0.88 | -0.94 | -0.22 | +0.76 |
| GBP/USD | +0.88 | +1.00 | -0.86 | -0.18 | +0.69 |
| USD/CHF | -0.94 | -0.86 | +1.00 | +0.35 | -0.78 |
| USD/JPY | -0.22 | -0.18 | +0.35 | +1.00 | -0.45 |
| XAU/USD | +0.76 | +0.69 | -0.78 | -0.45 | +1.00 |
Python Automated Correlation Matrix Engine
import MetaTrader5 as mt5
import pandas as pd
import numpy as np
def compute_forex_correlation(symbols: list, timeframe=mt5.TIMEFRAME_D1, bars: int = 90):
mt5.initialize()
close_data = {}
for s in symbols:
rates = mt5.copy_rates_from_pos(s, timeframe, 0, bars)
if rates is not None and len(rates) > 0:
df = pd.DataFrame(rates)
# Logarithmic returns provide stationarity for statistical rigor
df['log_ret'] = np.log(df['close'] / df['close'].shift(1))
close_data[s] = df['log_ret']
mt5.shutdown()
returns_df = pd.DataFrame(close_data).dropna()
correlation_matrix = returns_df.corr(method='pearson')
return correlation_matrix
if __name__ == "__main__":
pairs = ["EURUSD", "GBPUSD", "USDCHF", "USDJPY", "AUDUSD", "USDCAD"]
matrix = compute_forex_correlation(pairs)
print("=== 90-DAY FOREX CORRELATION MATRIX ===")
print(matrix.round(2))
Risk Rules for Correlated Portfolios
- Correlation > +0.75: Treat two trades as a single exposure. Split your standard risk budget in half (e.g., 0.50% on EURUSD and 0.50% on GBPUSD).
- Correlation < -0.75: Buying EURUSD and buying USDCHF simultaneously cancels directional return while doubling broker commission and swap spread fees.