Looking at the MSCI World Index historical performance, some striking patterns emerge. On average, markets experience a maximum intra-year decline of 15% — that's the typical peak-to-trough swing investors should mentally prepare for within any given year. Flip the script though, and you'll find the average intra-year maximum gain sits at 23%. What's interesting here isn't just the numbers themselves, but what they reveal about market behavior: volatility cuts both ways, and the upside tends to outpace the downside when you zoom out. For traders and portfolio managers watching global equity exposure, these metrics offer a useful baseline for understanding how much turbulence is baked into the normal operating environment.