Updated
Updated · Morningstar · Aug 24
Morningstar US Micro Cap Index Jumps 45.7%, Beating Broad Market as AI and Biotech Fuel Rally
Updated
Updated · Morningstar · Aug 24

Morningstar US Micro Cap Index Jumps 45.7%, Beating Broad Market as AI and Biotech Fuel Rally

3 articles · Updated · Morningstar · Aug 24

Summary

  • 45.7% trailing-year gains through Aug. 17 lifted the Morningstar US Micro Cap Index far ahead of the Morningstar US Market Index’s 22.8%, extending micro-caps’ outperformance over large-, mid- and small-cap benchmarks.
  • AI enthusiasm and spending drove much of the surge, with fiber-optics, chip-material and former crypto-miner-turned-data-center stocks helping the iShares Micro-Cap ETF beat the small-cap market; medical-treatment hopes also sent Praxis Precision Medicines sharply higher.
  • 33% average returns for small-cap funds with 51% to 100% in micro-caps topped the roughly 26% gain for funds with less than 19.6% exposure, and similar results appeared when funds were grouped by average market capitalization.
  • 18%-plus tech weightings and heavier exposure to lower-quality companies produced stronger category rankings among micro-cap-heavy funds, underscoring that much of the rally has come from more speculative names.
  • Slightly positive flows over the past year suggest investors are noticing, but Morningstar said many tiny stocks still face the same valuation and AI-spending sustainability risks as larger peers.

Insights

Could the explosive 2026 micro-cap rally be a dangerous speculative trap hiding behind the artificial intelligence boom?
With low-quality stocks driving this historic surge, what happens to these fragile companies when tech spending finally cools?