TOKYO: Japanese rubber futures plunged on Friday, snapping a 4-day rally and sliding from 6-month high hit the previous day, as a newly identified coronavirus variant in South Africa spooked investors and sent the yen higher against the US dollar.

Osaka Exchange’s rubber contract for May delivery finished 10.4 yen, or 4.1%, lower at 246.3 yen ($2.2) per kg. But for the week, it still gained 7.2%.

Britain said it was concerned by the variant spreading in South Africa that might make vaccines less effective and imperil efforts to fight the pandemic.

The yen rallied, making yen-denominated assets less affordable when purchased in other currencies.

The rubber contract on the Shanghai futures exchange for May delivery fell 455 yuan to finish at 15,240 yuan ($2,385) per tonne.

The front-month rubber contract on Singapore’s SICOM exchange for December delivery last traded at 175.9 US cents per kg, down 2.9%.