Hong Kong topped global rankings in terms of initial public offering volumes in the first half of 2018 and highly anticipated technology listings that are in the works in the six months ahead are expected to give markets an additional boost.

The Chinese territory recorded an estimated 98 IPOs in total in the first half of the year — in comparison, the New York Stock Exchange saw 35 IPOs in the same period — but, when it comes to IPO proceeds during that time, Hong Kong came in fifth, according to EY. Hong Kong's main board, together with its Growth Enterprise Market, is forecast to have raised 50.2 billion Hong Kong dollars ($6.4 billion) in the first six months of 2018.

That's around one third of an estimated $18.6 billion raised by the NYSE, which took the crown in first-half standings based on IPO proceeds. Also besting Hong Kong in those rankings were the Nasdaq, the Shanghai Stock Exchange and the Deutsche Boerse, which raked in $11.4 billion, $10.1 billion and $8.9 billion, respectively.

But things are only expected to heat up further for Hong Kong's IPO market in the months ahead, with a number of high profile companies — including several well-known technology names — expected to come to market this year. Among those names are Xiaomi, a consumer electronics company known for its smartphones, telecommunications infrastructure operator China Tower and Meituan-Dianping, an online platform for food delivery and other services.

"The second half of the year will be totally different from the first half," Ringo Choi, EY's Hong Kong-based Asia Pacific IPO leader, told CNBC's "Street Signs." "We expect that the second half will be a very, very busy time for us."

EY forecasts a total of HK$200 billion ($25.5 billion) in funds will be raised by IPO activities in Hong Kong in 2018.

Among the factors contributing to EY's "cautiously optimistic" outlook for Hong Kong's IPO markets are recent reforms to the Hong Kong Stock Exchange's listing rules and regional "opening-up policies" such as plans for the Greater Bay Area initiative.

As for the mainland market, EY expects the first China Depository Receipt, a scheme that will let mainland investors hold a form of shares in Chinese companies listed overseas, to be issued in the second half of the year.

"I think at the moment, they are very cautious about the CDR. That's why they are just allowing those very big unicorns or some listed companies, like BAT (an acronym referring to Baidu, Alibaba and Tencent), to go back to the mainland," Choi said.

That came after Xiaomi indicated last week that the company did not have a time frame for its mainland share offering. Reuters reported that issues related to CDR valuation were behind the delay, but Xiaomi later refuted that claim.