AS MILLIONS of Hong Kongers prepare to hand out packets stuffed with cash to mark the lunar new year, the hottest envelopes are coming from an unlikely source: global investment banks.

The red packets, often embossed with gold or signs from the Chinese zodiac, are in huge demand on a vibrant secondary market even though banks give them away for free. This year’s design from UBS Group AG is commanding the highest price, selling for more than HK$10 ($1.30) per envelope on Facebook Marketplace and Carousell Pte. That’s more than 50% above second-ranked Credit Suisse Group AG and almost triple the price being paid for those from local rival HSBC Holdings Plc.

Red envelopes containing cash are an annual tradition across much of Asia as a way to bring good luck for the upcoming year of the tiger. Known as laisee in Cantonese and hongbao in Mandarin, they are handed out to everyone from colleagues and customers to friends and family. Designs can take months to evolve with banks often including classic emblems like flowers and goldfish. The ritual is taken so seriously that the final layout usually requires approval from the top executive ranks.

Zodiac symbols, such as the tiger used by Credit Suisse, are even more attractive for collectors because they only come around once every 12 years. Hong Kong companies are estimated to spend as much as HK$300 million ($38.5 million) annually on red packet printing.

While the era of electronic payments has seen the rise of so-called e-laisee, giving out delicately designed paper envelopes remains part of a decades-long practice to pay respect to local customs. Close to 7,000 packet listings were created in the first half of January, double the pace of the year earlier, said Kevin Huang, managing director of Carousell Hong Kong in an email response. The most popular bank searches were for UBS, HSBC and DBS Group Holdings Ltd.

Most buyers online are purchasing them as keepsakes. Saby Cheng, a buyer and seller on Carousell, said she has been collecting banks’ packets for at least four years. While she expected the branded items’ price to rise over the time, she kept most of them and would only resell the surplus.

Spokespeople for UBS, Credit Suisse, Goldman Sachs Group Inc., Deutsche Bank AG, DBS and Morgan Stanley declined to comment while representatives of HSBC and BNP Paribas SA didn’t respond to requests for comment. — Bloomberg