Gourmet Master Co. stock plunged as the cafe operator got caught in the crossfire with China over Taiwan President Tsai Ing-wen's visit to an outlet in the US for a cup of coffee.

The shares slumped 7.5 per cent in Taipei trading Thursday, wiping $US120 million ($165 million) from its market value, after a newspaper in China published calls to boycott the chain for hosting the Taiwanese leader at a store in Los Angeles. Tsai's Democratic Progressive Party supports independence for the island, a policy opposed by China.

Taiwan's President Tsai Ing-wen's visit to a coffee shop has led to a market plunge for the company. Credit:AP

The Communist Party-run Global Times yesterday reported the incident earlier this week had angered Chinese consumers as it demonstrated Gourmet Master's support for Tsai. The cafe operator, which counts the mainland as its biggest market, issued a statement on its China website stating its support for the so-called 1992 Consensus that the island and mainland are both part of "one China".

The incident highlights the political risks of tapping the market in China with a population 60 times that of Taiwan. In 2004, Chi Mei Optoelectronics Corp.'s chairman stepped down after being singled out for his pro-independence views. International airlines were given a July 25 deadline to show Taiwan as part of China on their websites.