Wall Street's main indexes opened higher Thursday, buoyed by optimism that major technology companies could avoid U.S. President Donald Trump's latest tariffs on chip imports.

The Dow Jones Industrial Average rose 237.0 points, or 0.54%, at the open to 44430.09. The S&P 500 rose 29.3 points, or 0.46%, to 6374.32​, while the Nasdaq Composite rose 155.6 points, or 0.73%, to 21325.01. 

Apple's shares climbed 2.9% in premarket trading, having risen 5.1% and led gains on Wall Street in the prior session, after Trump said the iPhone maker will invest an additional $100 billion in the U.S., bringing its total commitment to $600 billion over the next four years.

Trump also announced a tariff of about 100% on imports of semiconductors but said it would not apply to companies that are manufacturing in the U.S. or have committed to do so.

Shares of chipmakers including Nvidia, Advanced Micro Devices and Intel rose in the range of 0.9% to 2.2% in premarket trading.

Meanwhile, Eli Lilly plunged 12.3% after reporting data on its late-stage oral weight-loss drug. The drugmaker also raised its full-year profit forecast.

Trump's higher tariffs of 10% to 50% on dozens of trading partners took effect on Thursday.

Still, expectations of policy easing by the Federal Reserve - sparked by some disappointing economic data, particularly the July payrolls report - as well as optimism around AI spending by companies have kept markets near record highs.

All eyes are on the initial jobless claims report, set for 8:30 a.m. ET, as investors look for fresh clues on the labor market after last week's disappointing payrolls data that triggered a dramatic repricing of the Federal Reserve easing path.

Traders are now betting almost fully on a September rate cut, with at least two moves expected this year, CME FedWatch showed.

"Equity markets continue to edge higher as Fed officials are sounding more dovish and global economic activity is resilient," said Elias Haddad, senior markets strategist at Brown Brothers Harriman.

Investors are also watching for Trump's interim replacement for Fed Governor Adriana Kugler in the coming days, amid expectations that the nominee would be a policy dove who will likely favor bringing interest rates lower.

Kugler's resignation leaves an opening at the seven-member Fed Board led by Chair Jerome Powell, who Trump has repeatedly criticized for not cutting borrowing costs. Powell's tenure is due to end in May 2025.

Second-quarter earnings barrage continued at full throttle. DoorDash topped revenue estimates and forecasted a stronger-than-expected gross merchandise value for the current quarter. Its shares jumped 8.4%.

Datadog jumped 10.4% after beating estimates for second-quarter results.