Over half a million people took to the streets of downtown Hong Kong earlier this month, on the 17th anniversary of the territory's reversion to Chinese rule, calling for more democracy and showing lingering unease about central rule from Beijing in the former crown colony.

The demonstration was a powerful display of opposition to China’s efforts to control who will be Hong Kong’s chief executive after 2017, when the post is supposed to be chosen by residents of China’s richest city.

The show of dissent irked the central government in Beijing, but it also rang alarm bells among analysts at HSBC, which before it became a British bank was originally called the Hong Kong and Shanghai Banking Corporation and was founded in the territory in March 1865.

"We reduce Hong Kong to underweight on concerns about negative news flow. "Occupy Central", a campaign for greater democracy, could sour relations with China and may hurt the economy," said the research note.

The note gave no further reasons for cutting the rating. There was an outraged reaction on Twitter – which is allowed in Hong Kong but not in China – and other social media, prompting HSBC to release an updated version which said: "We reduce Hong Kong to "underweight" on the risk of weak residential real estate prices, the slowdown in mainland tourist arrivals, the market's link to US interest rates (the Federal Reserve could raise rates next year) and weak earnings momentum."

“We also note recent concerns about negative news flow regarding the Occupy Central campaign.”

Big business apparently doesn’t like the Hong Kong democracy movement.

The Canadian, Italian, and Indian chambers of commerce issued a joint statement last month saying street protests risked damaging the city's reputation as a good place to do business, the South China Morning Post reported.

The big four global accounting firms advertised in the Hong Kong press warning that Occupy Central could force multinationals to quit the territory.

And there were accusations by Occupy Central that HSBC and Standard Chartered pulled advertising from the Apple Daily, a popular anti-Beijing newspaper, because of pressure from the Chinese government.

The banks have both denied this, saying they withdrew their advertisements for commercial reasons.