Will rotation towards tech (bc of market cap) involve high concentration risk &amp; another possible too-big-to-fail scenario micro-managed by regulators? Note $NDX is at historical highs while small caps are at historical lows.  $NDX / $SPX ratio &amp; slope are impressive &amp; alarming. https://t.co/wwFNN2pAj5 https://t.co/LNCkBhCEfk