AT&S surge makes Austria Europe's top stock market in 2026
A 459% rally in chip substrate maker AT&S has transformed Austria's traditionally bank-dominated ATX index into the eurozone's best-performing equity market this year.
Austria’s ATX index has climbed 21.3% since January, making it the best-performing major equity market in the eurozone this year. The outlier returns are not driven by the banks that traditionally dominate the Vienna bourse, but by a single semiconductor components manufacturer. AT&S has seen its shares surge 459% to €174, pushing its market capitalisation from roughly €1.25 billion to about €7 billion.
The gains sharply contrast with the sluggish performance of larger European neighbours. Germany’s DAX has risen just 1.6%, France’s CAC 40 is up 2.3%, and the broader Euro Stoxx 50 has gained 8.2%. Even Italy’s FTSE MIB, the closest continental competitor, trails the ATX by more than five percentage points.
A critical AI bottleneck
AT&S manufactures integrated circuit substrates, a highly specialised layer that sits between advanced artificial intelligence processors and their circuit boards. These components carry thousands of microscopic electrical connections, making them essential for chip performance but invisible to end users. Production requires extreme precision, leaving the market dominated by Japanese and Taiwanese firms like Ibiden and Shinko Electric, with AT&S standing as the only major European manufacturer.
Investor confidence is backed by a sharp improvement in the company's fundamentals. In its 2025/26 financial year, AT&S generated €1.8 billion in revenue, a 21% increase at constant exchange rates. Adjusted EBITDA climbed roughly 50% to €418 million, while free cash flow swung to a positive €236 million.
"2025/26 was a strong and pivotal financial year for AT&S," Chief Executive Michael Mertin said in May. Momentum accelerated in June when the Leoben-based company announced agreements with AMD and another major customer, reported to be Intel, to spend between €1.5 billion and €2 billion expanding capacity in Malaysia and China.
Reshaping a national index
The rally is forcing a structural shift in Austrian investment vehicles. While financial institutions still account for roughly half of the iShares MSCI Austria ETF—led by Erste Group at 24.2%—AT&S has vaulted to the fourth-largest holding at 5.9%. A year ago, its weight in the fund was negligible.
Austria is not about to rebrand itself as a technology hub. However, the AT&S boom demonstrates how acute bottlenecks in the AI hardware supply chain can single-handedly override the macroeconomic trends that typically dictate national index performance.
