Tech stocks slid as AI spending nears \$1tn — good moment to check how concentrated your 'diversified' index fund is?

The BBC reports the Nasdaq opened at its lowest level in more than two months, with Intel continuing to fall as AI spending heads toward \$1tn. A lot of people hold a broad market index fund and assume they're spread out, but the top handful of tech names make up a big chunk of the big US indexes. Not a 'sell everything' post, just curious: have you ever looked at your fund's top 10 holdings, and did it change how you allocate?