Austria's ATX Index Jumps 21% as semiconductor firm AT&S rockets 459%

The Vienna Stock Exchange’s ATX index has risen 21.3% since the start of the year, making it the best‑performing European equity market in 2026. The rally is driven primarily by AT&S (Austria Technologie & Systemtechnik AG), a relatively unknown supplier of integrated‑circuit substrates. AT&S shares have surged 459% from around €32 at the opening session to €174 by late December, increasing the company’s market capitalization from roughly €1.25 billion to about €7 billion in just over six months.

AT&S produces critical semiconductor substrates used in advanced AI processors, a sector that has outperformed many well‑known chipmakers. The Austrian market’s outperformance contrasts with modest gains in other Eurozone indices: Italy’s FTSE MIB up 16.1%, the Netherlands’ AEX 15.5%, Spain’s IBEX 35 11.5%, Germany’s DAX only 1.6%, and France’s CAC 40 2.3%. The broader Euro Stoxx 50 rose 8.2%, less than half the ATX’s return.