Shares of CSX (CSX - Get Report)  are rallyng on news that two activist investors have teamed up to target the railroad company. Railroad veteran Hunter Harrison, who worked with Pershing Square's Bill Ackman to revamp Canadian Pacific Railway  (CP - Get Report) , is now reportedly joining forces with another activist, Paul Hilal. The news came less than a day after CSX missed earnings estimates for the fourth quarter due to a decline in commodity prices and a drop off in coal shipments.  The activists are aiming to shake up management at CSX.