* Edmond Hui, Bright Smart Securities: "This wave of closings and layoffs affecting brokerage houses is the most severe we have ever seen"A historic drop of $4.6 trillion in the capitalization of the Hong Kong Stock Exchange is being felt in the city's financial industry, according to a Bloomberg analysis, which shows that 30 local brokerage houses have closed this year after a record of 49 houses closed in 2022.