One of the world's biggest IPOs hit the market Wednesday (December 19) to a disappointing start.
Shares for Softbank's mobile unit slumped more than 10 percent on debut, an unusually poor start in the Japanese market.
That makes it only the second to flop among major IPOs there in recent years.
As to why - many are pointing to a recent service outage at Softbank, one of Japan's largest telecoms operators.
During the IPO period, it suffered a rare nation-wide outage, which it said wouldn't affect earnings or dividends.
And adding to investor worries is the company's ties with China's Huawei.
It has the most exposure to Huawei among Japanese telecoms firms, amid worries that the company's gear could help Chinese spying.
Governments around the world are moving to shut Huawei out.
According to sources, Softbank has plans to replace its Huawei hardware.
A move that will likely be time-consuming and expensive.
One analyst told Reuters, retail investors are dumping shares after seeing the opening below IPO price, but they don't expect shares will fall much further.
Following its 23.5 billion dollar initial public offering, shares of Softbank Corp fell as far as 1,344 yen five minutes into trade - about 10 percent lower than its IPO price of 1,500 yen.
The broader Tokyo market was up 0.1 percent.