Cumulative flows for India and Malaysian bonds in full-year 2018 were negative, data showed.Foreign purchases of bonds issued in five Asian markets in 2018 fell sharply from previous year, data shows, as Sino-UStrade war and higher USyields prompted many investors to shy away from riskier assets.Data from central banks and bond market associations showed overseas investors bought a net $10.02 billion in Indonesian, Thai, South Korean, Indian and Malaysian bonds in 2018, compared with $49 billion in 2017.In December, South Korea and Indian bonds had biggest inflows among five countries, of $1.33 billion and $676 million respectively.However, cumulative flows for India and Malaysian bonds in full-year 2018 were negative, data showed.US Treasury yields surged last year on back of four rate hikes by Federal Reserve, narrowing interest rate gap between some high yielding Asian bonds and United States ones.Khoon Goh, head of Asia research at ANZ, said United States -China trade tensions, Fed rate hikes, wider emerging market concerns, a mid-year spike in oil prices and concerns over global growth were all headwinds impacting flows into Asia bonds last year."How these and other developments play out in 2019 will be key to whether portfolio inflows will return," he said.