Investors in most categories of investment funds lost money in October, with energy-heavy funds suffering the most, according to preliminary data on October investment-fund performance released today by Morningstar Canada.

The hardest hit among the indices were natural resources and the Canadian income trust, which declined by 8.6% and 8.1% respectively during the month.

With energy stocks making up about a quarter of the S&P/TSX composite index, domestic equity funds were the worst performers among industry-diversified categories. The Canadian equity (pure) index fell 5.7%, and the Canadian equity index didn’t fare much better, down 4.7%.

By comparison, the U.S. equity index had only a slight 0.3% loss, and the global equity index fell 1.3%. “Energy stocks in Canada and elsewhere were reacting to the retreat in both crude oil and natural gas prices during the month,” said Morningstar Canada analyst Brian O’Neill, in a release. “Among a multitude of factors, the Organization of Petroleum Exporting Countries announced it had more than adequate spare capacity to cover winter demand.”

O’Neill said the income trust sector, which is sensitive to changes in interest rates, was hurt last month in part because of expectations that interest rates will be headed higher. As well, he added, energy is the most heavily weighted industry sector among income trusts.

Only four of the 31 Indices were in positive territory during the month, including the two money market indices. Last month’s top performer was the Japanese equity index, which gained 0.8%. The index has now enjoyed four consecutive positive months, and is up 7.1% for the year to date.