The present invention relates to a multistage polymer in form of polymeric particles, its composition and its process of preparation. In particular the present invention it relates to a multistage polymer in form of polymeric particles made by a multistage process while the last stage comprises a polymer with a low molecular weight. More particularly the present invention relates to polymer composition in form of polymeric particles made by a multistage process comprising at least three stages while the last stage comprises a polymer with a low molecular weight, its method of preparation, its use as impact modifier in polymer compositions for composites comprising thermosetting resins or thermoplastic polymers and compositions and articles comprising it.