Wealthy investors in the US have responded to the volatile equity markets of the past two months by shifting into higher quality bonds, shortening duration and seeking more investment-grade securities, according to new research.

Within wealthy individuals' fixed income portfolios, allocations to investment grade debt rose by 3.6 percentage points in the period May 27 to yesterday, representing more than $1.6bn (€1.2bn) of fund flows, according to a report from US research firm Advisor Perspectives.