The announcement of a $50 million stock repurchase program by Cytek Biosciences has led to an increase in its share price. This is because buybacks are generally seen as a positive signal by investors, as they indicate that the company believes its stock is undervalued and has confidence in its future prospects. Additionally, buybacks can lead to a reduction in the number of outstanding shares, which can result in an increase in earnings per share and potentially boost the stock price.