STMicroelectronics' AI Growth Faces a Margin Test on October 29

STMicroelectronics has already shown that strong reported results are not enough. Its shares fell 18.7% after the previous quarter even though revenue rose 24.5% to $3.49 billion, adjusted earnings beat consensus and free cash flow turned positive. The October 29 report must show how quickly AI data-center demand can improve the company's mix and margins.

The last quarter established a better base. Adjusted earnings per share of $0.31 beat the cited consensus by 19.2%. Gross margin rose 1.3 percentage points to 34.8%, and free cash flow improved to positive $75 million from a $152 million outflow a year earlier. Management also reported a book-to-bill ratio close to two, meaning orders received were almost twice the amount billed during the period.

For the third quarter, ST guided to about $3.7 billion of revenue at the midpoint, up 16.2% from a year earlier, with gross margin near 37%. The cited consensus is $3.72 billion of revenue and $0.41 of adjusted earnings per share. Meeting those numbers would confirm growth, but the market's response will likely depend more on fourth-quarter guidance and the quality of that growth.

Data centers are the main source of acceleration. ST's July Form 6-K said it expected about $1 billion of data-center revenue in 2026 and that revenue could double in 2027 if current demand and customer engagements continued. That wording is more conditional than a booked $2 billion forecast. The company said communication equipment and computer peripherals could grow close to 60% in the third quarter and around 90% in the fourth, driven largely by optical connectivity.

The Amazon Web Services relationship adds both scale and potential dilution. The multi-year agreement includes warrants for up to 24.8 million ST shares tied to purchase targets, according to the original report. Investors need to weigh the revenue opportunity against the number of shares that could eventually be issued.

The weak point remains Power and Discrete, which recorded a negative 21.4% operating margin last quarter. Manufacturing restructuring reduced gross margin by about 0.6 percentage points, and management does not expect gross margin above 40% until the program finishes, currently targeted for the end of 2027. Tight microcontroller supply could also limit sales even if orders remain strong.

This creates a clear earnings test. A data-center beat with weak companywide margins would show that AI demand is growing faster than the rest of the portfolio but has not yet transformed profitability. Strong fourth-quarter guidance, better Power and Discrete economics and evidence that supply constraints are easing would make the recovery more convincing. Until then, ST's AI story is real, but it is still carrying the cost of weaker auto and industrial markets.