German and French equities slip as semiconductor sell-off drags indices lower

European benchmarks retreated on Tuesday in a session defined by a sharp sell-off in semiconductor shares that pulled the region's two largest indices into the red. The DAX closed 0.80 per cent lower at 26,128.36 and the CAC 40 shed 0.82 per cent to 8,509.36, while the Euro Stoxx 50 fell 0.95 per cent to 6,468.17. Breadth was decisively negative: of the 78 companies that traded, 46 fell and only 32 rose.

• DAX close: 26,128.36, down 0.80 per cent
• CAC 40 close: 8,509.36, down 0.82 per cent
• Euro Stoxx 50 close: 6,468.17, down 0.95 per cent
• Advancers: 32, decliners: 46
• STMicroelectronics: -7.64 per cent to €45.31
• Infineon: -7.63 per cent to €57.24

Semiconductor weakness sets the tone

Session movers, German and French equities, 2026-08-18 (close, percentage change, volume against the 20-day average)

Instrument	Close	Day	5-day	Volume vs avg
EssilorLuxottica EUR	163.9	+2.57%	-4.57%	0.91x
Dassault Systemes EUR	21.9	+2.48%	-0.90%	1.14x
Bayer EUR	48.74	+1.75%	-0.43%	1.18x
Siemens Energy EUR	154.28	-5.23%	-2.70%	1.04x
Infineon EUR	57.24	-7.63%	-8.93%	1.01x
STMicroelectronics EUR	45.31	-7.64%	-5.12%	1.04x
Source: exchange closing data via Yahoo Finance, session of 2026-08-18.

The session's dominant move was a near-simultaneous 7.6 per cent drop in both STMicroelectronics and Infineon, the two largest European-listed chipmakers by market value. STMicroelectronics, the Franco-Italian semiconductor group headquartered in Geneva but listed in Paris, closed at €45.31, down from €49.06 the previous session. The move came on volume of 1.04 times its 20-day average, indicating broad participation rather than a thin print. The shares have now fallen 17.5 per cent over the past month and sit 36.0 per cent below their 52-week high of €70.85.

Infineon, the German power semiconductor and automotive chip specialist, mirrored the decline almost tick for tick, closing at €57.24 from €61.97, a fall of 7.63 per cent on volume of 1.01 times the 20-day average. The stock has dropped 10.6 per cent over the past month and trades 35.6 per cent below its 52-week high of €88.83. The symmetry of the two moves, same magnitude, same sector, similar volume profiles, suggests a sector-wide reassessment rather than company-specific news. No material announcements were attached to either name in the session data.

Siemens Energy extends recent losses

The third-largest faller was Siemens Energy, which slipped 5.23 per cent to €154.28 from €162.80 on volume of 1.04 times its 20-day average. The gas turbine and grid technology group has now given back 2.7 per cent over the past five sessions, though it remains 3.7 per cent higher over the past month. The shares sit 19.5 per cent below their 52-week high of €191.66. As with the semiconductor names, no session-specific news was reported for Siemens Energy, leaving the move to be read as a continuation of profit-taking after a strong run earlier in the summer.

EssilorLuxottica leads the risers

On the upside, EssilorLuxottica rose 2.57 per cent to €163.90 from €159.80, the session's largest gain. The ophthalmic lenses and eyewear group, formed from the 2018 merger of France's Essilor and Italy's Luxottica, traded at 0.91 times its 20-day average volume, a touch below normal. The stock has fallen 4.6 per cent over the past five days and 3.3 per cent over the past month, and remains 49.4 per cent below its 52-week high of €323.80, a reminder of how far the name has retreated from its 2024 peak. No company-specific news was reported for the session.

Dassault Systèmes gains on partnership news

Dassault Systèmes, the French 3D design and simulation software group, added 2.48 per cent to €21.90 from €21.37 on volume of 1.14 times its 20-day average, the only riser to trade above its recent average. The move followed a reported partnership with Silvaco, a US-based electronic design automation and process technology company, aimed at advancing first-time-right semiconductor manufacturing. The collaboration links Dassault's 3DExperience platform with Silvaco's process simulation tools, a logical adjacency for a company whose software is already embedded in automotive, aerospace and industrial design workflows. The shares have risen nearly 20 per cent over the past month but remain 27.9 per cent below their 52-week high of €30.36.

Bayer edges higher amid mixed sector headlines

Bayer rose 1.75 per cent to €48.74 from €47.90 on volume of 1.18 times its 20-day average. The German life sciences group has been broadly flat over the past five days, down 0.4 per cent, but up 2.1 per cent over the month. It trades 9.6 per cent below its 52-week high of €53.92. The session data carried several pharmaceutical industry headlines, including a Phase III miss for EyePoint's Duravyu against Eylea, a sustainability recognition for WuXi Biologics, a rice trade expansion at Cibus, a Canadian authorisation for Lynkuet, and a Zacks industry outlook naming Bayer alongside Eli Lilly and Johnson & Johnson, but none directly concerned Bayer's own pipeline or earnings. The move appears to reflect general pharmaceutical sector rotation rather than a specific catalyst.

Sector rotation, not broad panic

Reading across the six most extreme movers, the session tells a story of sector rotation rather than indiscriminate selling. The semiconductor complex, STMicroelectronics and Infineon together, accounted for the bulk of the index drag, while Siemens Energy's decline extended a short-term pullback in capital goods. On the other side, the risers came from three unrelated sectors: eyewear and medical devices (EssilorLuxottica), industrial software (Dassault Systèmes) and pharmaceuticals (Bayer). Volume ratios clustered around one times the 20-day average for almost every name, indicating that the moves occurred in normal liquidity conditions without the spikes that often accompany panic selling or speculative buying.

The indices themselves remain within striking distance of their 52-week highs: the DAX is 1.7 per cent below its peak of 26,573.50, the CAC 40 is 2.8 per cent below 8,755.03, and the Euro Stoxx 50 is 1.7 per cent below 6,577.20. That proximity to recent highs, combined with negative breadth, suggests a market pausing after a summer rally rather than embarking on a sustained correction. The next test will be whether the semiconductor weakness spreads to automotive and industrial customers, many of whom are DAX constituents, or remains contained within the chip supply chain. STMicroelectronics sits at the bottom of its 52-week range, 36 per cent off its high, a level that will attract attention from both value hunters and momentum sellers in the sessions ahead.