The positive reaction in Sonic Automotive's stock price can be attributed to the earnings per share beating expectations, which often serves as a key indicator of financial health and operational efficiency for investors. Despite the revenue miss and the decline in net income, the company's actions such as share repurchases and the declaration of dividends demonstrate a commitment to returning value to shareholders and may instill confidence in the company's future prospects. These factors combined with the company's statement about being well-positioned for future success contribute to the positive short-term impact on the stock.