Ariad Pharmaceuticals shares skyrocket more than 70 percent after it strikes deal with Takeda

Ariad Pharmaceuticals (ARIA) investors are having a good day.

Shares of the biotechnology firm zoomed 73 percent higher — its best trading day in 17 years — on Monday after Ariad said it is being bought out by Takeda Pharmaceuticals (Tokyo Stock Exchange: 4502.T-JP), a leading Japanese pharmaceutical company.

Takeda agreed to buy Ariad for $24 per share in cash, or about $5.2 billion. The deal is expected to close by the end of next month. Both Takeda and Ariad's boards signed off on the deal.

"This transaction is a great outcome for shareholders of Ariad and Takeda. Both Ariad and Takeda are passionate about helping cancer patients, and I believe the talent and resources of Takeda coupled with Ariad's pipeline and people will accelerate the development of cancer treatments, Ariad Chairman Alexander Denner said in a release.

"The acquisition of Ariad is a unique opportunity that will enable us to positively impact the lives of more patients worldwide, advance our strategic priorities and generate attractive returns for our shareholders," said Christophe Weber, Takeda's president and chief executive officer.

Ariad's stock was on a roll in 2016, rising 99.04 percent. For 2017, the stock has already surged around 90 percent, after accounting for Monday's gains.

ARIA 1-year chart

Source: FactSet

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