Volume Spike Investor

Mosaic Co. (NYSE: MOS) shares are up roughly 12 percent to $50 on early premarket volume of about 20,000 shares. Speculation is rising that Vale SA (VALE) may make a $25 billion bid for Mosaic, following a report in the publication Estado. Some other agriculture and fertilizer stocks are rising in premarket trading on the news, including Potash Corp. (NYSE: POT), up more than 3 percent to $91.14 on early volume of more than 6,000 shares. — Mike Tarsala