Investors’ already downbeat sentiment in March turned even grimmer in April, according to the latest Bank of America Global Research global fund manager survey, released Tuesday. Fund managers’ April cash levels surged to 5.9% from 5.1% in March and 4% in February, the highest cash level since the 9/11 attacks and well above the 10-year average of 4.6%. Investors’ cash allocation jumped 13 percentage points from March to net 54% overweight, the highest reading since October 2008 and the second highest reading in the survey’s history, according to BofA.