This disclosure relates to a block copolymer composition comprising a tetra-branched block copolymer (IV) having a true number average molecular weight of 40,000 to 120,000 represented by the general formula (A-B)4X; a tri-branched block copolymer (III) having a true number average molecular weight of from 30,000 to 90,000 represented by the general formula (A-B)3X; di-branched block copolymer (II) having a true number average molecular weight of from 20,000 to 60,000 represented by the general formula (A-B)2X; and a linear diblock copolymer (I) having a true number average molecular weight of from 10,000 to 30,000 represented by the general formula A-B; where A represents a polymer block of a mono alkenyl arene; B represents a polymer block of a conjugated diene, wherein the B has a true number average molecular weight ranging from 7,000 to 20,000 g/mol; and X represents the residue of an alkoxy silane coupling agent.