Considering 30-days investment horizon, Cablevision Systems Corporation is expected to under-perform the Directv. In addition to that, Cablevision is 2.47 times more volatile than DIRECTV. It trades about -0.34 of its total potential returns per unit of risk. DIRECTV is currently generating about -0.15 per unit of volatility. If you would invest 4,848 in DIRECTV on April 25, 2012 and sell it today you would lose (211.00) from holding DIRECTV or give up 4.35% of portfolio value over 30 days.
Diversification
Poor diversification
Overlapping area represents amount of risk that can be diversified away by holding Cablevision Systems Corp. and DIRECTV in the same portfolio (assuming nothing else is changed)