Why MannKind Corporation Stock Broke Down in April

MannKind Corporation (NASDAQ:MNKD), the maker of the inhaled insulin product Afrezza, had yet another bad month in April. Specifically, the biotech's shares lost a quarter of their value last month, according to S&P Global Market Intelligence. 

What sent MannKind's stock spiraling downwards? On April 6, the biotech announced another secondary offering of common stock and warrants in an effort to raise a mere $28 million.