Futures tracking Wall Street's main indexes were muted Wednesday as investors awaited more data for clues on the state of the labor market, while a relentless rally in long-term U.S. Treasury yields kept markets on edge.

Adding to investor anxiety was the ouster of Speaker Kevin McCarthy by some Republicans in the House of Representatives just days after the government narrowly averted a shutdown.

While the 30-year Treasury yield crossed above 5% for the first time since August 2007, the 10-year and five-year yields hit their highest since 2007.

Megacap growth stocks including Microsoft, Meta Platforms, Nvidia and Tesla were down about 0.2% each in premarket trading, with Apple shedding 0.9% following a KeyBanc downgrade to "sector weight" from "overweight."

At 7:06 a.m. ET, Dow e-minis were up 9 points, or 0.03%, S&P 500 e-minis were up 0.5 point, or 0.01%, and Nasdaq 100 e-minis were down 5 points, or 0.03%.

The CBOE volatility index, Wall Street's "fear gauge," briefly hit a five-month high and topped its long-term average of 20.

A day after U.S. job openings unexpectedly rose in August, investors will closely monitor September ADP National Employment data at 8:15 a.m. ET and non-farm payrolls data on Friday for more clues about a fairly resilient labor market.

"Markets had become overly confident in pricing a rapid easing of the Federal Reserve's monetary policy," said UBS Global Wealth Management's Chief Investment Officer Mark Haefele, who expects near-term choppy and range-bound trading in equity markets.

On the political front, Haefele noted, "Absent a new House speaker, no action can be taken on bills, from routine matters to the funding of the federal government ... increasing the risk of a government shutdown in late November."

The Institute for Supply Management's non-manufacturing Purchasing Managers' Index, S&P Global's final composite and services PMI surveys, factory orders and remarks by Fed policymakers including Chicago President Austan Goolsbee and Board Governor Michelle Bowman will also be monitored during the day.

Traders' bets of at least another 25-basis point interest rate hike in November and December stood at 29% and 44%, respectively, according to CME's FedWatch tool.

All three major U.S. stock indexes ended more than 1% lower on Tuesday, with the Dow turning negative on a year-to-date basis for the first time since June.

Chipmaker Intel gained 1.9% on Wednesday on plans to operate its programmable chip unit as a standalone business and hold a public offering for stock in the business over the next two to three years.

Eli Lilly said the head of its diabetes and obesity division, Mike Mason, will retire by the end of the year. The drugmaker's shares fell 1%.