Golden Week,” or the holiday following China’s National Day on Oct. 1, is a popular time for mainland tourists to visit Hong Kong -- and freely dispense with their cash there. Top Chinese art auction houses with operations in Hong Kong are hoping to ride that wave, vying for the cash out of mainlanders’ deep pockets, by hosting the biggest sales in their history.

Poly Auction and China Guardian are up against Sotheby’s, which is also taking advantage of Golden Week by hosting a five-day bumper sale in celebration of its 40th year in Asia. Sotheby’s fall sale in the mainland is also typically slated for the same week, the Wall Street Journal reported Friday.

“Timing is important, and this is the time all the collectors gather,” said Hu Yanyan, Hong Kong president of Guardian, which last year held its fall sales in the city at the same time as Sotheby’s.

Hong Kong serves as the world’s gateway to China, and similarly, the Chinese auction houses view Hong Kong as their gateway to the international market, which is strategically important for their growth.

“In Beijing, we follow the economy, and that’s been on a downward trend for us. But in Hong Kong, we’re growing and getting bigger,” said Zhao Xu, executive director of Poly in Beijing.

Both firms are hosting their biggest sales in their brief histories in Hong Kong. Poly is hosting a three-day sale at the Grand Hyatt, offering around 2,000 items with a total valuation of $89.7 million, compared to the 409 lots it offered last year, which generated $66.8 million over two days.

Guardian has a two-day sale at the Island Shangri-La Hotel, with 600 lots worth an estimated $14.3 million. Last year it offered 358 lots, generating $23.9 million in just one day.

The items on offer from both firms are sourced outside China, with many lots coming from the U.S. Poly, in particular, pursues consignments among the American-Chinese community, regularly touring California and New York and advertising in local Chinese media outlets to encourage people to sell their treasures, the Wall Street Journal reported.  

Poly and Guardian, whose global rank is third and fourth, respectively, did not land in Hong Kong until last year -- and the special administrative area is still the only place outside mainland China where the two houses have operations. Before then, the Hong Kong auction scene was dominated by Christie’s Sotheby’s, the world’s two largest auction houses.

While traditional Chinese paintings are the top-sellers in Beijing, Poly said in Hong Kong that its most popular category is modern and contemporary art, pointing to Hong Kong’s international clientele. The two Chinese firms have learned in their short time there that what sells in Beijing is not necessarily going to do well in Hong Kong.

With Poly and Guardian getting into the Hong Kong market, both Sotheby’s and Christie’s are invading the mainland market that was previously dominated by the domestic Chinese houses. Last month, Christie’s held its first sale in Shanghai, and Sotheby’s held two small events in Beijing with local partner Gehua. But both foreign firms are forbidden from the Chinese government from trading “cultural relics,” which means traditional Chinese paintings and antiques -- the two highest-selling categories in mainland China -- will remain Poly and Guardian’s turf.

“I don’t see them as competition,” said Zhao, referring to Christie’s and Sotheby’s, the Wall Street Journal reported. “The regulation won’t change anytime soon. It’s a measure to protect local industry.”