World investors increased cash holdings in January as they braced for a choppy year with markets buffeted by conflicting forces such as diverging monetary policy and rising geopolitical risks, a Reuters poll shows.br A monthly survey of fund managers in the United States, Japan, Europe and Britain found the average allocation to cash in balanced portfolios jumped 1-12 percentage points to 7 percent -- the highest since May 2012. Forty-four institutions took part in the poll.