Billions of dollars are flowing out of Chinese markets in a ‘seismic’ change in capital flows despite a flurry of actions to shore up confidence

Chinese stocks rebounded on Monday morning after Beijing unveiled a raft of measures meant to halt their nearly monthlong slide. But the rally proved to be short-lived as foreign investors used it as an opportunity to unload $1.1 billion of mainland Chinese equities, according to Bloomberg data.

China’s CSI 300 Index, which tracks the performance of the 300 largest firms on the Shanghai and Shenzhen stock exchanges, rose as much as 5.5% on Monday before paring most of its gains to end the…