The Exchange Fund's total assets amounted to $961.5 billion as at July 31 - $18.4 billion less than a month earlier. Both foreign currency assets and Hong Kong dollar assets fell, by $16.2 billion and $2.2 billion.

The Hong Kong Monetary Authority said the decrease in foreign-currency assets resulted from valuation losses on foreign-currency investments and the sale of foreign currencies for Hong Kong dollars. They were partly offset by an increase in repurchase agreements and income from foreign-currency assets. 

The decrease in Hong Kong-dollar assets was mainly due to fiscal drawdowns. These were partly offset by the purchase of Hong Kong dollars from foreign currencies and valuation gains in the market value of Hong Kong equities the Exchange Fund holds.

The Currency Board Account shows that the monetary base at the end of July was $253.1 billion, a decrease of $0.8 billion, or 0.3%, from the end of June. 

The decrease was mainly due to a decrease of $0.7 billion in the market value of outstanding Exchange Fund bills and notes.

The backing assets fell $1.1 billion, or 0.4%, to $283.3 billion.