Shares of Aehr Test Systems cratered 19% over the Russell reconstitution week and were trading at $86.24 on June 29, down 6.1% on the day, after FTSE Russell removed the semiconductor-testing company from several Russell indices during its annual rebalancing. No company-specific bad news triggered the drop — this is a story about what happens when the index plumbing turns against a small stock.
Trillions in Passive Money Just Stopped Buying. Approximately $12.2 trillion in assets are benchmarked to Russell U.S. indexes.
The newly reconstituted indexes took effect after U.S. market close on June 26. When a stock is dropped from an index, every fund that tracks it must sell — mechanically and without regard to the company's fundamentals. For a thinly traded name like AEHR, with roughly 31.5 million shares outstanding and just 136 employees, that forced selling can swamp normal demand and amplify losses well beyond what business conditions warrant.
The Rank-Day Timing Worked Against AEHR. In 2026, the rank day fell on April 30 , when FTSE Russell freezes market-cap snapshots to decide index membership. AEHR's market cap was about $1.54 billion as of early April — likely near the borderline for inclusion. The stock subsequently surged on a record $41 million production order from a leading hyperscale AI customer announced on April 16 , but that rally may have come too late or introduced volatility that complicated its ranking. The breakpoint for the Russell 2000 was set at $5.7 billion this year , well above AEHR, meaning its removal was not about graduating to a bigger index — it was about falling out entirely.
Fundamentals Tell a Different Story. During its most recent quarter, Aehr recorded bookings of $37.2 million, over 3.5 times higher than its revenue , and its effective backlog hit a record $50.9 million. The company makes equipment that stress-tests chips for AI data centers and electric vehicles — markets expanding rapidly. Yet AEHR trades at a price-to-sales ratio above 61 times trailing revenue of just $45.3 million , and the average analyst 12-month price target sits at just $63.67 — roughly 26% below the current price. Insiders have collectively sold $35 million more than they bought over the past 12 months.
What Comes Next Is a Liquidity Test. Without index-fund demand as a backstop, AEHR's shareholder base must now be supported entirely by active investors who believe the AI-testing boom justifies a valuation many times the company's actual revenue. The December reconstitution — the first under FTSE Russell's new semi-annual schedule — offers another shot at re-entry, but only if the market cap holds. For now, the stock's biggest risk isn't its technology; it's the gap between a red-hot order book and a price that already assumes years of flawless execution.