The stock dropped to as low as HK$393.20, compared with its offer price of HK$436, after opening at HK$419.60.
It was last down 8.5 percent at HK$398.80.
The broader market was also weaker, with the Hang Seng Index falling 0.6 percent at one stage and the tech index down 1.2 percent.
RoboTechnik was one of four companies to start trading in Hong Kong on Tuesday, in a test of investor appetite for new share offerings amid a revival in the city’s IPO market.
Hong Kong IPOs, including secondary listings, have raised US$46.54 billion so far this year, a 94.3 percent jump from a year earlier, LSEG data showed.
Printed circuit board maker Shenzhen Kinwong Electronic opened seven percent lower at HK$65, versus its HK$69.88 offer price, after raising HK$5.1 billion.
The stock was last up 9.5 percent at HK$76.55.
Specialty chemicals and semiconductor materials maker Red Avenue New Materials Group opened 9.1 percent lower at HK$40 versus its HK$44 offer price, after raising about HK$3 billion.
Robotics technology company Direct Drive Tech opened 4.1 percent higher at HK$22.48, versus its HK$21.60 offer price, after raising HK$1.08 billion.
“I don’t think the IPO market has the same punch as before,” said Dickie Wong, executive director of research at uSmart Securities.
“Because of US-China tension in AI and chips sector and fears that AI is getting frothy, names in AI, robotics and PCB are no longer being chased the way they were.
“People are picking more carefully now. Theme alone is not enough. Valuation and recent momentum matter more. Subscription demand and first-day trading have both cooled a lot.”
RoboTechnik makes equipment for photovoltaic cell manufacturing and assembly, and testing systems for silicon photonics devices used in optical interconnects for data centres and artificial intelligence infrastructure.
It sold 11.88 million Hong Kong shares in the base offering.
Cornerstone investors, including Temasek, Sunpeak Asset and IvyRock, agreed to buy about US$232.4 million of shares, the prospectus showed.
The company plans to use listing proceeds for research and development, expanding production capacity and speeding up deliveries, global sales and service operations, as well as for potential acquisitions and working capital.
RoboTechnik reported first-half 2026 net profit of 6.3 million yuan, from a 12.2 million yuan loss a year earlier.
Revenue rose 145.1 percent to 608.1 million yuan, driven mainly by silicon photonics assembly and testing equipment. (Reuters)