https://www.reuters.com/article/us-china-didi-global-investors/didi-cybersecurity-probe-blindsides-shareholders-days-after-debut-idUSKCN2EB195 >Chinese regulators have gained a reputation for aggressive action, but even hardened investors were shocked by the announcement of a probe into ride-hailing firm Didi just two days after its $4.4 billion New York stock market debut.