The positive reaction in Sportradar's stock price can be attributed to the company's better-than-expected Q4 financial results, which typically signal strong operational performance and future growth potential. Additionally, the authorization of a $200 million share repurchase program is often viewed positively by investors as it reflects the company's confidence in its financial health and a commitment to returning value to shareholders. These factors combined are likely to have a short-term positive impact on Sportradar's stock price.