Biotech Values

[Summer2762]

Does anyone know why the stocks go up before such offer? For example, OGXI was up 7.6% today.

The simple explanation that the companies take advantage of the higher pps does not apply in this case as the SEC docs filed by OGXI indicates that the offer was prepared yesterday (e.g., it has the following sentence: "On March 14, 2012, the last reported sale price of our common stock on The NASDAQ Capital Market was $16.20 per share.")

I observed this behavior in many other stocks as well.

Is it because there are clauses that prevent investors from being in short position if they want to participate? (So stocks go up because short position must be closed)? Or is there any other simple explanation?

Thanks
-summer