The value of deposits that have entered Hong Kong's banking system surged for the third time in a row in August as investors bring in cash to invest in the wave of new initial public offerings (IPOs) and secondary listing. According to the Hong Kong Monetary Authority (HKMA), deposits had increased by about HK$387.9 billion or roughly $50 billion last month.

On Wednesday, the city's de facto central bank revealed that total deposits made at the end of August had already reached HK$14.8 trillion. The 2.7 percent increase in August was preceded by a similar jump in July and a 1.6 percent increase in June. The HKMA stated that even without counting IPO loans, which typically require the opening of deposit accounts, total deposits for August would have still been higher by 0.9 percent.

The amount of hot money, or short-term cash meant for capital market investing, had dramatically increased since April as more investors flock to the city to take advantage of new secondary listings. The recent share sales conducted by companies such as NetEase, Yum China, and JD.com has attracted investors from mainland China and other parts of the world.

 The wave of new money coming into the city is expected to grow as more Chinese firms announce plans to list their shares. Alibaba's digital payment unit, Ant Group, recently filed to launch a dual IPO in both Hong Kong and Shanghai. The dual listing is expected to become the world's largest fundraiser once it is launched. Ant Group received approval for its dual listing from the Shanghai Stock Exchange on September 18. The transaction is still awaiting approval from regulators in Hong Kong.

Due to the massive influx of new capital into the city, the HKMA has had to step in on several occasions to weaken the Hong Kong dollar. Just this month, the bank has had to step in 15 times, selling a total of HK$69.4 billion worth of the city's currency to buy U.S. dollars. This pushed the exchange rate to around HK$7.75 per U.S. dollar.

The current rate is inching ever closer to the limits under the city's currency peg system. Under the system, the local currency has to be pegged to the U.S. dollar at around HK$7.80. The HKMA typically intervenes to ensure that the rate stays between HK$7.75 and HK$7.85.