The Hong Kong Monetary Authority is HK's 'central bank' and they are in to prevent the HKD from rising beyond its peg.
- HKMA injected HKD 1.14bn into the banking system (in effect this is sale of HKD 1.39bn)
The linked exchange rate is kept between 7.75 and 7.85
Lower USD/HKD is higher HKD, its knocking on the door of 7.75