The negative short-term impact on Ulta Beauty's stock price is primarily due to the company's Q4 financial results and FY24 revenue guidance not meeting market expectations, which typically leads to a decrease in investor confidence and share price. However, the announcement of a new $2.0 billion share repurchase program may provide some support to the stock price by signaling the company's confidence in its future prospects and potentially reducing the number of shares outstanding, which can increase earnings per share.