"Rapidly rising prices are once again putting pressure on potential homebuyers to get into the market as well as encouraging sellers to delay and ask for higher prices," he said. "High home costs are adding to social concerns and should recent capital inflows end up on bank balance sheets, lower mortgage rates could add further momentum to the market."
Read More Hong Kong's housing market is 'least affordable': survey
Hong Kong's home prices have more than doubled since 2008, driven higher by a flood of cheap money from developed markets' central banks in the wake of the global financial crisis.
The special administrative region's property market has become the world's least affordable, according to a Demographia International Housing Affordability Survey, published in January. The survey found average home prices were 14.9 times gross annual median household income, the highest level ever recorded in the survey's 10-year history.
The number of new and existing homes sold in July jumped to 7,792, after remaining below 6,000 a month for the past year, according to government data.
Read More What London can learn from Hong Kong's property market
The increased activity appears to be driven by "optimistic homebuyers" seeking out seemingly affordable primary launches amid limited secondary market supply and relatively low overall transaction volumes, Lawrence said. He noted that data from Inland Revenue's Buyers Stamp duty receipts suggests foreign buyers and investors buying through companies account for only 4 percent of transactions over the past two months.