China’s embattled top securities regulator, Xiao Gang, has offered to resign, sources said, after perceived mismanagement wiped more than $5 trillion off the capitalization of the Shanghai and Shenzhen stock markets since they peaked last June. The 57-year-old chairman of the China Securities Regulatory Commission (CSRC) tendered his resignation last week after his brainchild, a “circuit breaker” mechanism to limit stock market losses, was blamed for exacerbating a sharp sell-off, a source with ties to the leadership and a financial industry source told Reuters.