China's securities regulator is tightening rules on short selling. Starting today, China Securities Corp, the country's largest stock lender, will stop lending shares to brokerages. From July 22nd, investors will need to put up more collateral to short sell stocks. This caused a huge surge in$Hang Seng TECH Index(800700.HK)$Index recently. Has the trend reversed upward? How high could prices climb? Follow me for fresh insights Short-term trading instru...