12:15 PM EDT, 09/18/2024 (MT Newswires) -- US equity indexes fell in choppy midday trading Wednesday ahead of the Federal Reserve's policy announcement later in the afternoon.

The S&P 500 index fell 0.2% to 5,624.3, with the Nasdaq Composite down 0.3% to 17,574.1 and the Dow Jones Industrial Average 0.1% lower at 41,551.5. Except for gains in consumer staples, energy, and healthcare, all the other sectors fell intraday.

The Federal Open Market Committee statement and Summary of Economic Projections are scheduled to be released at 2:00 pm ET, followed by Federal Reserve Chair Jerome Powell's press conference at 2:30 pm ET.

According to data compiled by the CME Group from interest-rate traders, the probability of a 50 basis-point cut stood at 61% on Wednesday afternoon. The remaining 39% likelihood was a 25 basis-point drop, implying the Fed is all set to deliver its first rate cut.

The Fed will reduce its target rate by 25 basis points while issuing a dovish message via the so-called dot plot and Powell's discourse at the press conference, a research note from Macquarie said. "If we are wrong, and the Fed cuts by 50bps, we expect that the 'dovish' implication will be offset by guidance (from Powell) for 25bps rate cuts for the last two FOMC meetings of the year."

Most Treasury yields rose, with the 10-year yield up 4.9 basis points to 3.69%, and the two-year rate was 6.1 basis points higher at 3.65%.

In economic news, August housing starts were up 9.6% from the previous month to a 1.356 million annual rate, above expectations compiled by Bloomberg for a 1.32 million rate after a decrease to a 1.237 million pace in July. Building permits rose 4.9% to a 1.475 million rate in August, above the 1.41 million rate expected and following a drop to a 1.406 million rate in July. Homes permitted but not started increased, implying an optimistic outlook for housing starts next month.

In company news, Wolfe Research downgraded ResMed ( RMD ) to underperform from a peer-perform stock rating, with a price target of $180. Shares of the company fell 5.8% intraday, the worst performer on the S&P 500.

West Texas Intermediate crude oil futures slipped less than 0.1% to $71.21 a barrel.