Chinese tech stocks including majors like Alibaba and Tencent rallied this week, pushing them to highs not seen in more than a year.

Chinese stocks are on a tear, and prominent figures including billionaire investor David Tepper and Goldman Sachs’ Scott Rubner are all in.

China’s problems run deep, but policymakers are changing their tone. Experts are taking note but are still wary as previous moves haven’t worked.