Assuming 30 trading days horizon, Atlantic Coal PLC is expected to generate 1.74 times more return on investment than Gravity. However, Atlantic is 1.74 times more volatile than Gravity Ltd. It trades about -0.07 of its potential returns per unit of risk. Gravity Ltd is currently generating about -0.23 per unit of risk. If you would invest 40.00 in Atlantic Coal PLC on April 25, 2012 and sell it today you would lose (10.00) from holding Atlantic Coal PLC or give up 25.0% of portfolio value over 30 days.
Diversification
Modest diversification
Overlapping area represents amount of risk that can be diversified away by holding Atlantic Coal PLC and Gravity Co. Ltd in the same portfolio (assuming nothing else is changed)