A whole national market fell 2.7% today because two companies fell 5%. Sit with that before you scroll past it.

The KOSPI stopped being an index a while ago. It became a leveraged bet on memory chips wearing a diversified costume — and today the costume slipped. Korean investors who thought they owned "the market" owned Samsung and SK Hynix and a rounding error.

Here's the part that should keep you honest: the S&P 500 looks the same right now. A handful of AI giants carry the whole thing. Nikkei holders learned this in 1989, when a market that felt permanent turned out to be a few names holding up the sky.

So run the number. Add your top holdings across every fund you own. If those dropped 5% tomorrow — are you diversified, or are you Korea? #risk #sizing