The top two executives at Alibaba Group Holding bought a combined HK$120 million (US$15.3 million) worth of the company’s ordinary shares on Monday in a vote of confidence after the tech giant unveiled one of China’s biggest fundraising rounds dedicated to AI. The share placement, the first since Alibaba’s listing in Hong Kong in 2019, was oversubscribed three times amid strong investor sentiment, according to people familiar with the situation, reflecting what analysts said was “stronger growth...