United Microelectronics shares fell approximately 10% on Monday following the pricing of a $1.8 billion convertible bond sale. The Taiwanese chip foundry filed the transaction terms with the U.S. Securities and Exchange Commission at 9:27 a.m. ET, just before the start of trading. The decline occurred despite a broader market rally in the S&P 500, indicating that the stock movement was specific to UMC.
The deal consists of two $900 million tranches that carry no interest payments. Holders have the option to exchange the bonds for new shares beginning three months after the October 13 issuance date. If the bonds do not convert, investors receive slightly less than their initial investment, with annual yields of -0.25% and -1.35% for the two tranches respectively. This structure means UMC is effectively being paid to borrow the funds.
UMC stated that if all bonds convert, existing shareholders would face approximately 2.34% dilution. This dilution would only occur if the stock price rises above the conversion prices. The company noted that this would represent the first significant increase in its diluted share count since 2022, as the figure has remained largely stable in recent years.
The 10% share price drop erased more than $5 billion in market value, a figure exceeding three times the size of the bond deal. While some of the decline may be mechanical due to investors shorting the stock to hedge convertible positions, UMC's balance sheet does not indicate extensive financial risk. The company plans to use the proceeds for machinery, equipment, and new plant facilities, pointing to an increased capital spending budget that could impact free cash flow until new capacity is utilized.
The market reaction appears disproportionate to the fundamentals of the deal, as UMC is securing debt at a low cost of capital. New shares will only be issued if the stock performs well above current levels. However, if the shares do not rise, UMC is obligated to repay $900 million on the short tranche in April 2028. The company's next earnings report will provide further details on the scale of its spending plans.