I'm confused by your question. If you take 4% of the principal and the market does not return at least 4%, your principle has shrunk. This does not account for

I'm confused by your question. If you take 4% of the principal and the market does not return at least 4%, your principle has shrunk. This does not account for inflation either. The Trinity study that the 4% rule comes from is based on having some assets left after 30 years, not the original principle being intact. Trinity study: https://en.wikipedia.org/wiki/Trinity_study https://en.wikipedia.org/wiki/Trinity_study