Fan Bao founder and CEO of China Renaissance speaks at the WSJD Live conference in Laguna Beach, Calif., in 2016.Mike Blake/Reuters Chinese dealmaker Bao Fan, founder of investment bank China Renaissance Holdings Ltd, has gone missing in the latest disappearance of a top business executive, unnerving investors and sending its stock down as much as 50% on Friday. The mainland China-based boutique bank said in an exchange filing late Thursday the company had been unable to contact Bao. China Renaissance’s board was not aware of any information that indicated Bao’s “unavailability is or might be related to the business and/or…