This note provides a replication of Martin's (Quarterly Journal of Economics, 2017, 132(1), 367-433) finding that the implied volatility measure SVIX predicts US stock market returns up to 12-month horizons. I find that this result holds for both S&P 500 and CRSP market returns, regardless of whether returns include or exclude dividends. The predictability largely disappears after the SVIX index is replaced by an exponentially weighted moving average measure of realized volatility, suggesting that SVIX holds incremental forward-looking information compared to realized volatility, despite the high correlation between the two volatility measures.
