Mosaic (MOS) is seeing relative strength and calls are active Friday. Shares are up $1.15 to $43.91, even as the “ag” stocks (POT, AGU, IPI, TRA, MON) deliver a mixed performance. In the options market, 27K MOS calls traded, compared to 4,355 puts. Today’s call volume represents 13X the expected for midday action. July 45 and 50 calls are the most actives, with buyers driving the flow. It’s not clear why, as there is no obvious news on the stock. Implied volatility is up to 67.5 from 65.5 yesterday.