Assume a fictitious world where there are four stocks:

General Electric (GE)

CitiGroup (C)

British Petroleum (BP)

FaceBook (FB)

The market is in equilibrium where CAPM assumptions hold (e.g. homogeneous expectations, efficient markets, zero transaction costs, etc.)

Express the equilibrium condition for this universe of stocks in terms of each stocks return contribution and risk contribution. For notation purposes, you can use the symbols r_mkt & _mkt to represent the markets return & risk and r_f to represent the risk-free rate. (Note: Students can either type or neatly hand-write the relationship and upload a picture or file containing the expression.)