The announcement of a $1 billion accelerated share repurchase program by United Therapeutics is likely to be viewed positively by investors, as it reflects the company's confidence in its financial health and future prospects. Such programs often lead to a reduction in the number of shares outstanding, potentially increasing earnings per share and the stock price in the short term. Additionally, the planned paydown of the revolving credit facility further signals strong financial management and may reduce interest expenses, contributing positively to the company's bottom line.