Reuters/ Brian Snyder

Adage Capital is located on the 52nd floor of the John Hancock Tower

Shares of Puma Biotechnology (PBYI) were going absolutely bonkers Wednesday morning following a successful trial of a breast cancer drug.

The stock surged about 283%, or about $167, since the opening bell.

At least one hedge fund is probably really pleased with this investment.

The largest shareholder of Puma Biotechnology is Adage Capital Management, a Boston-based hedge fund founded by Phil Gross and Robert Atchinson .

According to the latest 13F data, Adage last held 5,686,668 shares. That means they had made about $950 million on the position since the opening bell Wednesday.

Adage first reported its position in Puma Biotechnology on Dec. 31, 2012. The fund held about 5.2 million shares then. From that time until Tuesday's market close, shares of Puma Biotechnology had risen 214%.

And all those who sold out of the position before this news broke are probably kicking themselves right about now.

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