Technoprobe, the world's largest producer of probe cards used in semiconductor testing, will be added to the FTSE MIB on September 21, 2026, replacing diagnostic group DiaSorin, which will move to the MidCap index. The FTSE Italia Index Series Technical Committee confirmed the change, which takes effect after market close on Friday, September 18. FTSE Russell will publish a notice on September 21 detailing the exact share counts and investibility weights for the revised index composition.
With a market capitalization of roughly 17.5 billion euros as of September 2, Technoprobe is one of Italy's most valuable listed companies. Its shares have more than doubled in value since the start of 2026, propelled by surging demand for semiconductor testing equipment driven by the artificial intelligence buildout. The company, listed on Euronext Milan, is already a component of the FTSE Italia All-Share and related technology sector indices. It manufactures probe cards, the high-density connectors used to verify chips during production, a market expanding rapidly as semiconductor designs grow more complex to support AI workloads.
The addition will markedly increase the technology sector's weighting in the FTSE MIB, which currently stands at around 4 percent, almost entirely due to STMicroelectronics. Technoprobe's inclusion will nearly double that share, reflecting the growing importance of Italy's semiconductor supply chain. The health care sector, which today accounts for just over 1 percent through DiaSorin, faces further erosion if Recordati proceeds with its ongoing tender offer. The change will also force passive funds that replicate the benchmark to rebalance their holdings, concentrating buy and sell orders in a narrow time window around the effective date, with potential short-term volatility implications.
