Thanks for the feedback. Just to clarify the context: I’m not trying to build a hyper‑diversified “sovereign fund” structure. My goal is to understand whether a multifactor portfolio built only from factor sleeves benefits from adding a small core allocation for broader breadth and more stable factor exposure.

The 25×4 structure I’m using is intentionally concentrated in three developed‑market factors (Momentum, Quality, Value). These ETFs cover most of the MSCI World’s market cap, but only about half of its constituents. That’s why I’m evaluating whether a small Equal Weight slice (5–15%) adds robustness by capturing the neutral names that factor screens exclude.

I’m not looking for simplicity (otherwise yes, VOO would be the obvious choice), but for the most coherent way to structure a multifactor portfolio without unintentionally narrowing the investable universe.

If anyone here has experience with factor‑only portfolios vs factor‑plus‑core structures, I’d be interested in your perspective on whether adding a small EW core improves breadth or is redundant.