For most investors, the first Monday in October will be just another trading day. But after a turbulent year in the stock market, investors may want to pay more attention to the new session of the Supreme Court.

On the docket is the case of Jones v. Harris Associates. If you question why your mutual funds charge so much to manage your investments, you’ll want to follow the proceedings.

The case, brought by shareholders against a mutual fund’s adviser, could lead to lower fees for many of the 45 percent of households owning mutual funds. Potentially, it could also rebalance a pecking order where individuals working to build a retirement nest egg can pay twice as much as big institutional clients.

The fund industry, which has largely succeeded in beating back fee challenges, warns a victory for individual investors could unleash lawsuits targeting many of the nearly 8,000 funds holding more than $10 trillion. Much of the cost from that litigation could ultimately be passed onto investors. The industry says investors have been served well by a fee-setting standard in place since 1982.