The particular technical and institutional constraints of electric systems and electricity markets result in a significant difference between the feasible strategy set of generation companies in electricity markets and that of investors in capital markets. Despite its importance， this issue is seldom discussed in existing literature. This shortage can constitute an obstacle to the application of GMTS research fruits. For the purpose of addressing the deficiencies of the current GMTS research， the analytic tool of efficient frontier is employed to study the effects of the technical and institutional constraints on the feasible region of GMTS. One of the conclusions drawn in this paper is that the shape of GMTS efficient frontier is different from that of the efficient frontier of ordinary investment markets， which theoretically demonstrates the importance of considering the unique constraints of the electric power market in the GMTS decision.