New York, January 20, 2026, 12:53 ET — Regular session
Shares of United Microelectronics Corp surged roughly 16% Tuesday, pushing the Taiwan chipmaker to lead the semiconductor sector while broader U.S. markets dipped. UMC climbed $1.52 to $10.82, hitting an intraday high of $10.93.
This shift is significant as investors target “mature-node” chips—older manufacturing tech still crucial for power chips, sensors, and connectivity components in cars and data-centre equipment. Even a hint of firmer pricing here can rapidly boost margin forecasts.
It arrives just ahead of a packed slate of Taiwan tech updates, as traders seek solid data to back a swift rerating instead of chasing another rumour-fueled squeeze.
UMC’s shares listed in Taipei surged to hit the daily limit at NT$68.7 before settling back to gains around 6% to 7%, according to Taiwanese media. Ho Wen-kao, an analyst at Gu-De Investment Advisory, attributed the jump to rumors that prices for 8-inch wafer foundries might climb between 5% and 20%. He cautioned that the sharp spike could trigger profit-taking. 1
Taiwan’s Economic Daily News reported that foreign investors have remained steady net buyers of UMC shares this year. The paper added that “co-packaged optics” (CPO) is emerging as a new catalyst for the stock. Citing supply-chain sources, it said UMC’s Singapore Fab 12i P3 expansion has entered the technical introduction and pilot production phase, aiming for mass production by 2027. UMC confirmed the new Singapore facility will focus mainly on 22nm and 28nm processes, targeting markets like communications and automotive. Silicon photonics is among the specialty technologies the company is actively developing. 2
The jump followed a shift to a defensive stance across markets, sparked by fresh U.S. tariff threats targeting parts of Europe. Volatility measures climbed amid pressure on major stock indexes, according to a Reuters report. 3
Shares connected to Taiwan’s chipmaking network gained traction after Micron announced it would acquire Powerchip Semiconductor Manufacturing’s P5 fab on the island for $1.8 billion in cash. The move boosted optimism around Taiwan’s semiconductor sector. 4
UMC, a contract chipmaker, produces integrated circuits for clients in sectors like communications and consumer electronics. It stands as one of Taiwan’s main foundries, trailing only market leader TSMC. 5
Yet the rally shows a clear vulnerability: the “8-inch price hike” story remains largely speculative, and prices can slip fast if demand eases or buyers resist. A sharp one-day jump often invites short-term sellers, especially if upcoming data falls short of the market’s raised hopes.
Investors are eyeing UMC’s upcoming quarterly earnings report and investor call set for Jan. 28, with the firm’s monthly sales figures to follow on Feb. 5, per the company’s investor relations calendar. 6
Traders are focused on any clear signals about 8-inch wafer pricing, utilization levels, and if silicon photonics/CPO is shifting from buzz to actual sales.
