Aspen Investment Fund LLC appears to be trying to take advantage of the poor stock performance of Vivus Inc. (NASDAQ:VVUS), as the mysterious firm said it is mulling a bid to buy the biotech.

On May 28, Aspen disclosed in an SEC filing on that it had acquired a 9.7% stake and "is currently contemplating a conditional non-binding offer to acquire Vivus at a total consideration of $640 million." The firm plans to submit the