Asian stock markets plunge, trading halt in Seoul

In Tokyo, the Nikkei 225 index fell by more than 3 percent. Hong Kong was down around 2 percent at 8:30 a.m. local time in Sweden.

The decline was triggered by a sharp drop on the tech-heavy U.S. Nasdaq stock exchange, which fell more than 1 percent yesterday evening, and where futures trading ahead of the opening this afternoon indicate a further decline of over 2 percent.

Among other things, recently listed SpaceX fell more than 16 percent on Monday evening.

The fact that the Japanese yen is at its lowest level against the dollar since 1986 is also causing concern.