The Hang Seng just had its best day in five months

The index rose 1.3% to end above 28,000 points for the first time since July. Friday was the first day of trading in Hong Kong since the Christmas holiday.

The index has been volatile this year. It plunged 8.6% in the third quarter as the city's protests and the US-China trade war weighed on sentiment. It then recovered losses in the fourth quarter and is now up 9.2% for the year.

Asian markets were otherwise mixed after China released solid economic data.

China's Shanghai Composite spent most of the day in positive territory and briefly rose 1.1%. But it erased all those gains at the close and finished slightly lower.

South Korea's Kospi rose 0.3%, while Japan's Nikkei 225 was down 0.4%.

China's industrial profits rose 5.4% in November from a year earlier, reversing a 9.9% plunge in October, government statistics showed Friday morning.

The reversal was mainly because industrial companies increased production in November, the government said in a press release. But the overall economy is still under a lot of pressure, which means corporate profitability could remain volatile, it added.

Meanwhile, the Hong Kong-based life insurance company AIA jumped 2% Friday after the company announced plans to take advantage of a change to China's rules about its financial sector. It was one of the Hang Seng's best performers.

AIA, which is listed in Hong Kong, said Thursday that it will convert its Shanghai office into a wholly owned subsidiary — something it was unable to do before China announced that it would scrap foreign ownership limits on the financial sector next year. The restrictions on wholly owned subsidiaries in the life insurance sector lift January 1, with additional industries to follow.

Right now, AIA can only operate in restricted areas where it has offices approved by Chinese regulators, including Shanghai and Beijing. But with a wholly owned subsidiary based on the mainland, AIA can expand its business more freely there, which means it could potentially grow its base of clients.

In Tokyo, Japan Display, a screen supplier to Apple, surged 6.9%. The liquid crystal display maker is in talks with Apple and Sharp to sell its main factory, according to Nikkei Asian Review.