The S&P 500 and the Dow treaded water, while Nasdaq fell Wednesday, as losses in tech heavyweights Apple and Nvidia limited broader gains and investor focus turned to the U.S. Federal Reserve's interest-rate decision, expected later in the day.

Markets widely expect the central bank to hold its lending rate steady in its decision, due at 2 p.m. ET.

"Without clarity on the macro impact of a range of government policies, primarily tariffs, but also on tax policy and the labor market impact of immigration policy, we think it's fair to expect limited guidance from the Fed today," Goldman Sachs economists said in a note.

At 10:56 a.m. ET, the Dow Jones Industrial Average rose 45.64 points, or 0.10%, the S&P 500 lost 18.94 points, or 0.31%, and the Nasdaq Composite lost 131.70 points, or 0.67%.

Six of the 11 S&P 500 sectors were in the red, with technology stocks leading declines with a 1.1% fall.

Nvidia dropped 3.3% after gaining close to 9% on Tuesday. Its shares were hammered on Monday, after Chinese startup DeepSeek launched AI models it said were cost-effective and ran on less advanced chips compared to OpenAI.

Apple shed 1.1% after brokerage Oppenheimer downgraded its rating to "perform" from "outperform." The iPhone maker is scheduled to report quarterly earnings later this week.

Of the 112 companies in the S&P 500 that have reported earnings so far, 75.9% reported numbers above analyst expectations, according to data compiled by LSEG.

Meanwhile, shares of semiconductor firms and related equipment makers advanced after Dutch firm ASML reported fourth-quarter bookings of 7.09 billion euros ($7.39 billion), far exceeding expectations.

KLA Corp rose 1.5%, Applied Materials was up 1.3%, Lam Research gained 0.5% and Micron Technology added 1.1% in morning trading.

The Nasdaq jumped 2% in the previous session, while the S&P 500 rose close to 1%, as Nvidia and other artificial intelligence-linked tech shares recovered somewhat from the steep losses suffered earlier in the week.

Markets have been on edge due to worries around U.S. President Donald Trump's proposed tariffs, which could exacerbate inflationary pressures and slow rate cuts.

The December reading of the personal consumption expenditures price index, a crucial metric in assessing the inflation trajectory, is due on Friday.

Among earnings, T-Mobile added 7.4% after the company forecast stronger-than-expected annual subscriber growth driven by increased demand for its affordable premium 5G plans.

Danaher shed 7.7% after the life sciences company missed estimates for fourth-quarter profit, due to soft demand for tools and services used in drug development by its biotech and pharmaceutical clients.

Earnings from Magnificent 7 stocks Microsoft, Facebook-parent Meta and Tesla are expected after markets close.

Cybersecurity and cloud services company F5 jumped 5.1% after forecasting second-quarter revenue above estimates and posting a first-quarter revenue beat.

Advancing issues outnumbered decliners by a 1.09-to-1 ratio on the NYSE, while declining issues outnumbered advancers by a 1.29-to-1 ratio on the Nasdaq.

The S&P 500 posted 18 new 52-week highs and two new lows, while the Nasdaq Composite recorded 36 new highs and 52 new lows.

($1 = 0.9628 euros)