NISA Investment Advisors' Pension Surplus Risk index fell 60 basis points in July to 9.1%.
NISA said the decrease was due to a drop in volatility for both the return-seeking asset and liability components of the index.
Asset volatility fell 61 basis points in the month to 7.79%; liability volatility decreased 25 basis points to 8.45%.
The average funded status of plans in the universe fell 20 basis points to 86.2%.
