Japan's central bank just announced it's planning to offload its ETF holdings. Sounds straightforward, right? Not quite. At the pace they're currently talking about, this unwinding process could stretch for over 100 years.

Think about what that actually means. The Bank of Japan has accumulated massive ETF positions over years of aggressive monetary policy. Now they're facing the practical reality of how to exit those positions without destabilizing markets. The math is brutal—even at a measured, deliberate selling pace, you're looking at a time horizon that extends well beyond anyone currently working in finance.

This isn't just about one central bank either. It reflects a bigger picture: what happens when years of stimulus programs need to unwind? Asset holders—whether governments, institutions, or markets—are grappling with liquidity constraints and exit strategies. The gradual approach signals caution, but it also hints at just how large these holdings have become.

For anyone tracking monetary policy flows and their ripple effects across asset classes, this is a reminder that central bank actions cast very long shadows.