【明報專訊】THE HONG KONG DOLLAR'S recent downward trend is an indication that capital is fleeing into the US Dollar. Judging from the way things are going, it will not be long before the HKD reaches the USD/HKD rate of 7.85, the point of so-called weak-side Convertibility Undertaking. That will trigger a response from the Hong Kong Monetary Authority (HKMA), which under the existing mechanism will have to buy Hong Kong dollars and sell US dollars.