Range-Based Covariance Estimation Using High-Frequency Data: The Realized Co-Range

We introduce the realized co-range, a novel estimator of the daily covariance between asset returns based on intraday high–low price ranges. In an ideal world, the co-range is five times more efficient than the realized covariance, which uses cross-products of intraday returns, when sampling at the same frequency. In Monte Carlo simulations, we find that for plausible levels of bid–ask bounce, infrequent trading and nonsynchronous trading, the realized co-range still improves upon the realized covariance. In a volatility timing strategy for S&P500, bond and gold futures, we find that the co-range estimates are less noisy, which results in lower transaction costs and higher Sharpe ratios.