China, the world’s second largest economy, has become the latest battlefield “fordotcom” companies with online financial exchange businesses booming. While, the traditional CAPM can’t price the online financial capital asset successfully, there is no theory of pricing online capital asset. In this paper we build an exchange online financial capital asset pricing model, which improves the performance of the CAPM in application. In our empirical results, the model ECAPM is more successful in pricing online financial capital asset rather than CAPM. Overall, our findings show some arguments of failure of online financial market in US, but of boom in China.