CMC Magnetics (TPE:2323) acquired 260,000 shares of Taiwan Semiconductor Manufacturing (TPE:2330) for NT$385.3 million, according to a Thursday filing.
Shares gained over 3% in Friday's late afternoon trade.
The shares were bought at an average price of NT$1,481.74 between Dec. 8 and Dec. 11, the optical data storage media manufacturer said.
Following the purchase, CMC Magnetics holds 747,000 TSMC shares worth about NT$1.04 billion, representing a 0.003% stake.