What happened

Shares of Forty Seven (FTSV) climbed 64.5% in March, according to data from S&P Global Market Intelligence. The immuno-oncology specialist's stock skyrocketed early in the month after it was announced that the company was on track to be purchased by Gilead Sciences (GILD 0.28%).

^SPX Chart

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Gilead Sciences announced on March 2 that it had reached terms to acquire Forty Seven in a $4.9 billion deal that valued the immuno-oncology company at $95.50 per share. Forty Seven's share price jumped following the news to a level close to the buyout bid, and stayed relatively stable throughout the rest of the month while the broader market experienced downward pressure stemming from the COVID-19 pandemic.

A person swabbing a cue tip inside a test tube.

Image source: Getty Images.

So what

Both companies' boards of directors unanimously approved the deal to buy Forty Seven, with the purchase set to be carried out by Gilead's Toro Merger Sub subsidiary. A tender offer was issued on March 10 by Gilead and has since been completed. Gilead Sciences stock climbed roughly 7.8% in March, largely due to investors' hopes that its antiviral drug remdesivir (which was previously tested as a potential treatment for Ebola) could be effective against COVID-19, but also due to momentum from the Forty Seven acquisition. 

Now what

Gilead and Forty Seven published press releases on April 7 announcing that the merger had been completed and that the smaller biotech company's stock had been converted at the agreed-upon price of $95.50 per share.  The deal was Gilead's second major acquisition push into the immuno-oncology space, the first having been its 2017 purchase of Kite Pharma for $11.9 billion.