STMicroelectronics stock drops 2.5% and loses top spot in CAC 40

A session decline that contrasts with the weekly rebound, in a CAC 40 under pressure

STMicroelectronics is down 2.38% to €45.53 in session, while the CAC 40 falls 0.46% and the SBF 120 falls 0.43%. The semiconductor manufacturer is thus among the strongest declines in the Paris index, alongside other financial securities. This decline comes after several sessions of gains that had brought the seven-day gain to nearly 6%, including Monday's advance at the top of the CAC 40.

The one-month performance remains in the red at -5.68%, and the three-month decline reaches 27.53%, which illustrates the fragility of the medium-term dynamics despite the week's upturn. ASM International, a comparable sector value, is also down 2.51% in session, while ASML Holding remains nearly stable at -0.09%, which tempers the extent of a purely sectoral movement. On the macro front, the prospect of a ECB rate hike on Thursday towards 2.5% weighs on growth stocks of which ST is part, in a context where European inflation has crossed back above 3% in August due to the energy surge.

Between the 20-day MA crossed and the 50-day MA distant, the chart configuration remains under tension

The price of €45.53 is held above the 20-day moving average set at €44.84, with a gap of 1.53%. This buffer remains modest, and any further deepening of today's decline could bring the stock into contact with this first threshold. Conversely, the 50-day MA at €50.63 is still 10% above the current price, a resistance whose crossing would require a sharp rebound. The RSI at 51 is neutral and signals no directly readable exhaustion, so the indicator does not rule out a continuation of the decline towards the support level at €42.22.

When publishing Q1 2026 results on July 23, the company had highlighted the expected contribution of NXP's MEMS sensors as a growth opportunity, while citing the volatility of tariff policies among its risks. According to the consensus of surveyed analysts, the stock is trading around 39 times expected earnings for the current fiscal year, a high multiple for a manufacturer that still shows marked margin pressure. The support at €42.22 remains the level to watch in the continuation of the session.