The value of the council’s investment fund fell by £36 million in the first half of the financial year.
Members at Monday’s policy and resources meeting heard the fund had dropped significantly from £415 million at the end of March, to £379 million at the end of September.
The council is now projecting a negative return for fund partners BlackRock and Baillie Gifford.
That was something acting finance manager Hazel Tait said was “unusual but not surprising”, given the financial climate.
She said they had “done what we can to minimise losses”.
Councillor Davie Sandison said he did not hold out much hope of seeing investments rise again in the short to medium term.
“We’re drawing beyond the sustainable level of our reserves,” he said.
He added that, coupled with the fact the fund had since dropped by £36 million, the council’s financial situation “sends a shiver down my spine”.
“We need to take stock of the situation,” he warned.
Political leader Emma Macdonald said the investment report was “really quite stark”.