In general, under an EMM, does there necessarily exist a replicating portfolio for every derivative?
I believe the answer to this is false. A simple example is a discrete time, trinomial model.
In a complete market, i.e. the EMM is unique, does there necessarily exist a replicating portfolio for (at least all European) derivatives?
In the only 2 models I know - being Black-scholes and Binomial model, this is true, but is this true in general?