United Microelectronics Corporation (UMC) is down 7.1% today at $24.00, largely due to the Taiwan Stock Exchange placing the stock under disposition, triggering a trading curb from July 8-15. - The sell-off is further intensified by investors taking profits after strong June sales and repositioning ahead of the July 8 ex-dividend date. - This follows a recent rally fueled by optimism around its Intel foundry partnership and double-digit June revenue growth.