Cargo containers are piled up at the Yantian port in Shenzhen, South China's Guangdong Province in December 2018. Photo: VCG

The GDP of the nation's "Silicon Valley" - Shenzhen, South China's Guangdong Province - surpassed its neighboring Hong Kong Special Administrative Region for the first time in 2018, as calculated by annual average exchange rates, according to figures released by Hong Kong on Wednesday.Both cities have their roles to play, as the nation's grand plan for the Guangdong-Hong Kong-Macao Greater Bay Area is becoming a reality and will usher in a new development chapter, experts said.Data from the Census and Statistics Department of Hong Kong showed its GDP grew 3 percent in 2018 to HK$2.845 trillion ($362.4 billion or 2.4 trillion yuan) based on the average annual exchange rates of the past year - HK$1.1855 per yuan - as shown on the department's website.Meanwhile, the GDP of Shenzhen was 2.4221 trillion yuan, up 7.5 percent year-on-year, according to figures released by the Shenzhen statistics bureau on February 1. The stellar figure brought Shenzhen, one of China's first special economic zones that opened up to the outside, into the top five among Asian cities."Shenzhen overtaking Hong Kong in GDP is no surprise as the two cities have different economic and industrial structures, with the former driven by mass advanced manufacturing and high technology, while the latter relies on its traditional edge in the services industry such as finance," said Mao Yanhua, a professor at the Institute of Guangdong, Hong Kong and Macao Development Studies at Sun Yat-sen University.Hong Kong's exports grew moderately for 2018 as a whole, but they slowed sharply late in the year as global growth eased and the trade conflict between China and the US took its toll, said the Hong Kong government in a press release on its website.Wang Lixin, vice mayor of Shenzhen's municipal government, said that driven by newly emerging industries, the city's total investment in research and development accounted for 4.2 percent of its 2018 economic output.The added value of these strategic industries rose by 9.1 percent year-on-year in 2018, Wang told a press conference on Thursday ahead of the China (Shenzhen) IT Summit, to be held at the end of March.Ma, a 29-year-old student from the mainland who's been studying in Hong Kong, told the Global Times on Thursday that "I don't feel that Hong Kong is going backward, but Shenzhen is leaping forward via strategic high-tech industries."However, a larger GDP does not mean everything. Per capita GDP in Hong Kong in 2018 was HK$381,870, equal to around 322,000 yuan according to the annual average exchange rate, which was well above Shenzhen's 200,000 yuan."Shenzhen still has a long way to go," said Mao. "The GDP gap between Shenzhen and Hong Kong will become larger in the future, but the criteria should not be economic growth."Shenzhen's rise has come with hard work by the local government to attract talent and prospective start-ups, according to a Beijing-based investment manager surnamed Jia. "The officials have a high standard of management and they are really listening to the needs of enterprises and thus improving their services, which is a good sign," Jia noted.But as the country continues to push for integration, both Shenzhen and Hong Kong have bright futures, analysts said."A golden opportunity has just kicked in as China rolls out the development plan for the Guangdong-Hong Kong-Macao Greater Bay Area, which can provide a new growth engine for Hong Kong's economy through its interconnection with Shenzhen and the other cities in the area," he said."Hong Kong is striving to attract some high-technology companies from Shenzhen to boost its industrial innovation, while it can also play its role as an international financial hub to promote cooperation with the rest of the area," he added.The Greater Bay Area aims to build a global economic and technological powerhouse in the country's south region that could be on par with bay areas in New York and San Francisco, according to the development plan unveiled by the State Council, China's cabinet, on February 18.