你说的应该是one fund theorem 和 two-fund theorem吧

two fund therorem只适用于只有风险资产的资本市场,而one fund theorem是适用于存在无线风险资产和风险资产都存在的资本市场,只能说更general的是one funds theorem,至于reaistic的话,也是one funds therorem,因为CAPM就是based on that..

one fund theorem:there is a single risky composition x* in the M-V set such that any MV-efficiency composition can be duplicated as a linear combination of x* and the risk-free asset.(因为此时的MV-efficiency边界是一条直线证明略(其实就是一个简单的最优话问题))

two-fund theorem:let x1 and x2 be two distinct MV-efficiency compositions. then any MV-efficiency composition can be duplicated as a linear combination of x1 and x2. (因为此时的的MV-efficiency边界是一个双曲线,证明略(其实就是一个简单的最优话问题))