In the shadow of Hong Kong's big banks, rows of currency exchange shops specialise in quick, anonymous transactions.
But behind the scenes, much larger deals are helping to move money at an unprecedented rate. Wealth is flowing from the mainland, through currency dealers in Hong Kong and beyond.
The leaked Mossack Fonseca documents have revealed to us how the families of China's leaders keep money offshore.
And now, a full analysis of the files by the International Consortium of Investigative Journalists shows that nearly one third of the firm's business came from its offices in Hong Kong and China - making China the firm's biggest market and Hong Kong the company's busiest office.
Destabilising the economy?
Mossack Fonseca's booming China business is evidence of an even bigger trend: the reliance of China's wealthiest people on offshore investments.
Around $1tn (£700bn) left China last year, draining the country's foreign reserves.
It is a shift that could destabilise the entire Chinese economy.
And the relatives of China's leaders are among those who have stashed their wealth abroad.
At least seven current and former leaders were found to have links to offshore companies set up by the Panamanian law firm, including the Chinese President, Xi Jinping, and two other top leaders.
