The Taiwan stock exchange said on Tuesday it is looking into unusual moves in the shares of HTC Corp one day before the smartphone maker announced a settlement with Apple.

HTC shares had jumped by their permitted daily limit on Friday, one day before a surprise announcement in the US that the company had agreed with Apple to end a long-running patent dispute.

“We are looking into whether there has been abnormal trading of HTC stocks,” said Michael Lin, a senior executive president of the stock exchange.