Volatility & Variance: Reading the Risk Fingerprint
MTUM.US (iShares MSCI USA Momentum Factor ETF) carries an annualised volatility of 17.4%, categorised as moderate relative to the long-run US equity benchmark of approximately 15%. SPY.US (SPDR S&P 500 ETF Trust) registers at 15.3%, a moderate reading by the same standard.
MTUM.US is marginally more volatile than SPY.US by 2.1% annualised. For most US long-term investors this difference is unlikely to be psychologically meaningful, though it will compound over multi-decade holding periods.
On the downside, MTUM.US's maximum peak-to-trough drawdown of 30.2% represents a severe bear-market drawdown over the study period. SPY.US's worst drawdown of 23.9% was a severe bear-market drawdown. SPY.US demonstrated stronger capital preservation characteristics, absorbing market shocks with less peak-to-trough damage.
When evaluating these two funds for a US-domiciled portfolio, it is important to consider that volatility and drawdown metrics are calculated on trailing historical data. Past standard deviations do not guarantee future behaviour, particularly around US Federal Reserve policy shifts, which have historically been the primary driver of cross-asset correlation breakdowns.