As equity valuations turn expensive amid the record breaking rally, financial planners are telling investors to diversify their stock portfolios globally and allocate 10-15% of their holding overseas over the next two years. Global markets have a low correlation with Indian stocks and help reduce risk. For instance, Indian markets have a 0.16% correlation with Wall Street, 0.25 with the World and 0.32 with Europe. ET spoke to financial planners,