Record Q3 Revenue of $1.2B Yet Stock Corrects on AI Doubts; DeepValue Stays Cautious on MPWR

What happened

Monolithic Power Systems reported record Q3 revenue of $1.2 billion, up 63% year over year, driven by surging AI accelerator demand and higher-value power modules. Despite these blowout numbers, the stock has corrected sharply as investors question the sustainability of AI investment cycles, with MPWR's growth heavily tied to that single end market. The DeepValue master report, written before this latest quarter, had rated the stock a potential sell at ~$950, citing extreme customer concentration, wafer purchase commitments, and a valuation with no margin of safety. The new revenue figure is far above the report's base-case expectations, suggesting AI demand was stronger than modeled, but the market's negative reaction shows it is pricing in future slowdown risk. Thus, while the fundamentals appear stronger momentarily, the concentration and cyclicality concerns from the report remain largely unaddressed, and the stock's correction may not be enough to create a bargain.

Implication

The 63% revenue jump to $1.2 billion validates near-term AI strength, but it also deepens MPWR's dependence on a volatile segment where order visibility is only 3-4 months and customers can reschedule without penalty. The stock's sharp correction from recent highs near $1,090 to around $950 reflects market recalibration, yet at current levels MPWR still trades at roughly 24 times trailing earnings and 77 times EV/EBITDA, leaving little room for disappointment. Our bear case of $750 (now perhaps 25% probability) prices in a slowdown in Enterprise Data growth and gross margin compression below 54% due to fixed wafer commitments, while the base case of $950 still offers no expected return. Even the bull case of $1,150 requires sustained >20% Enterprise Data growth and successful ramp of automotive and SiC, which, despite the strong quarter, has not been conclusively demonstrated. Therefore, we recommend trimming positions above $1,050 and refraining from new purchases until the stock approaches our attractive entry level of $750 or until we see clear evidence of AI demand broadening beyond the current large customer.

Thesis delta

The new article reveals Q3 revenue of $1.2B, up 63% YoY, which is dramatically higher than the $737M reported in Q3 2025 used in our original analysis, indicating that AI demand accelerated well beyond our base-case assumptions. This strong result increases the probability of our bull scenario (now ~30% versus 25%) and reduces the bear probability (now ~25% versus 30%), but it does not eliminate the risks of customer concentration and cyclicality that underpin our potential-sell rating. We maintain our rating and attractive entry of $750, as the stock's correction to ~$950 still leaves it priced for near-perfect execution.