If you would invest 1,550 in Yahoo! Inc. on April 24, 2012 and sell it today you would lose (12.00) from holding Yahoo! Inc. or give up 0.77% of portfolio value over 30 days.
Diversification
Weak diversification
Overlapping area represents amount of risk that can be diversified away by holding NYSE and Yahoo! Inc. in the same portfolio (assuming nothing else is changed)