U.S. stock futures were little changed on Monday night, with investors weighing the latest developments on the trade front to kick off a seasonally poor month for equities.

Dow Jones Industrial Average futures rose 41 points, or 0.09%. S&P 500 futures were higher by about 0.12% and Nasdaq 100 futures added 0.13%.

Those moves come after a federal appeals court on Friday ruled that most of President Donald Trump’s global tariffs are illegal. The U.S. Court of Appeals for the Federal Circuit determined in a 7-4 ruling that only Congress has the authority to apply sweeping levies. Trump called the decision “Highly Partisan” and has said that he will appeal the ruling to the U.S. Supreme Court.

“A Supreme Court ruling against the use of IEEPA on reciprocal tariffs would reduce the risk of broad-based tariff escalation, which is market-positive,” wrote Aniket Shah, head of of sustainability and transition strategy at Jefferies. “However, short-term uncertainty may rise as some trade agreements may need to be renegotiated.”

Those developments could weigh on sentiment to start a new trading month. September is historically the worst month for equities, with the S&P 500 averaging a 4.2% drop over the last five years, and falling more than 2% on average over the last 10.