China’s COVID-19 wave is rippling through the nation’s financial industry, with currency volumes falling as traders call in sick and banks activating backup plans to keep operations running smoothly. A sudden uptick in the number of sick traders was one reason behind the drop in onshore yuan-dollar spot volumes to the lowest level since April on Monday, five people familiar with the situation said, asking not to be identified discussing internal matters. Half of the currency traders at one Chinese bank in Beijing were off sick as of yesterday, one of the people said. The process of executing and confirming…