Volatility & Variance: Reading the Risk Fingerprint
VWRP.LSE (Vanguard FTSE All-World UCITS ETF USD Accumulation) carries an annualised volatility of 12.1%, categorised as moderate relative to the long-run US equity benchmark of approximately 15%. IWDA.LSE (iShares Core MSCI World UCITS ETF USD (Acc)) registers at 15.5%, a moderate reading by the same standard.
IWDA.LSE is marginally more volatile than VWRP.LSE by 3.4% 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, VWRP.LSE's maximum peak-to-trough drawdown of 15.3% represents a notable pullback over the study period. IWDA.LSE's worst drawdown of 24.1% was a severe bear-market drawdown. VWRP.LSE demonstrated stronger capital preservation during the period's worst stress events, which is particularly relevant for US investors approaching retirement or drawing down a portfolio.
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.