How Aehr Test Systems Stock Rose 144% Last Month

Shares of Aehr Test Systems (NASDAQ: AEHR) soared 144.2% in April 2026, according to data from S&P Global Market Intelligence. No, that's not a typo; the semiconductor test equipment maker more than doubled in price last month. Of course, seasoned Aehr investors saw the surge as a natural extension of prevailing trends. As of this writing on May 5, for example, Aehr's stock has gained a staggering 1,004% in 52 weeks.

Mixed earnings, but investors didn't care

Big moves have become the routine for Aehr and its investors. There were 21 market days in April. Aehr shares rose at least 5% on 7 of those days, led by a 25.7% increase on April 8. It also fell 5% or more on two occasions.

I won't dive in to explain all 9 of last month's significant price swings. Let's just focus on a handful of big days, looking for repeated patterns.

As it turns out, Aehr's investors aren't exactly craving perfect financials at this point. The company reported Q3 2026 results on April 7, and the numbers weren't that impressive. Net losses were slightly smaller than expected, but $10.3 million in sales fell short of analysts' expectations at $10.8 million. And management simply reiterated existing guidance targets based on Q3 results and current market trends.

Many stocks would fall on news like that, but I already highlighted the following day as the absolute highlight of Aehr's April action. You see, Aehr is collecting orders faster than it can make equipment. The backlog of unfilled orders was worth $38.7 million at the end of the quarter, up from $18.2 million in the year-ago period. That's the fuel for Aehr's fires.

On the earnings call, management highlighted a unique growth driver for the next few quarters. Some of Aehr's tools can be used to burn-in freshly manufactured semiconductor chips. The process weeds out manufacturing problems before they become costly product recalls, and generally extends the useful life of each burnt-in chip. Most chipmakers haven't made burn-in a standard part of their manufacturing process yet -- but that's changing.

Burn-in expansion should keep those Aehr system orders coming for a while. Investors are embracing that promising growth vector.

Image source: Getty Images.

Aehr's backlog keeps getting bigger

Aehr didn't have news of its own on most of the good days. The stock tends to rise when the semiconductor sector as a whole is surging, and that was a common theme in April 2026. That being said, Aehr also unveiled the largest order in its history on April 16, with a $41 million follow-on order from an existing hyperscale customer. The order included the Sonoma high-end testing system and several burn-in modules, with revenue-generating shipments expected to start in fiscal year 2027.

Including this order and other deals entered after the end of Q3, Aehr has added more than $92 million to its backlog in the second half of fiscal 2026.

The stock trades at lofty valuation ratios despite very small revenue streams and negative earnings. But I get why Aehr investors are getting excited about the company's explosive order growth. Just make sure you can deal with Aehr's valuation (608x forward earnings isn't for the faint of heart) and execution risks before buying the stock.

Anders Bylund has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.