Analysts see the deal, which was announced on December 5, as a way for HSBC to shift back towards its traditional banking business and raise funds.
In December, HSBC avoided US prosecution by agreeing to pay $1.92 billion in fines and to undertake sweeping reforms of its management and compliance systems in a deal with US regulators and justice authorities.
US authorities accused HSBC of intentionally breaking its sanctions on Iran and other countries, and laundering Mexican drug money to build its business.
Ping An, China's second largest life insurer, has previously said it did not plan any changes in strategy as a result of having a new stakeholder.
Ping An hit the headlines last year after the New York Times said that Chinese Premier Wen Jiabao's relatives benefited ahead of its 2004 Hong Kong listing by buying stock at a discount. It did not accuse Wen of any wrongdoing.
The Chinese insurer said at the time that the paper's reporting contained "serious inaccuracies, facts being distorted and taken out of context, as well as flawed logic".
Ping An Insurance closed up 5.29 percent to 50.77 yuan ($8.15) in Shanghai trading on Friday ahead of the announcement, and rose 1.87 percent to HK$70.85 ($9.13) in Hong Kong.
HSBC slid 0.34 percent to HK$88.00 in Hong Kong trading on Friday.