The Dow Jones Industrial Average gave back gains and closed lower on Thursday as investors pocketed some of their profits in what's been a solid week thus far.

The 30-stock Dow fell 224.48 points, or 0.51%, closing at 43,968.64.The S&P 500 lost 0.08% and ended at 6,340.00. The Nasdaq Composite advanced 0.35%, ending at 21,242.70. The major averages saw sharp swings during the session, with the Dow up more than 300 points at its high and off more than 390 points at its low.

The blue-chip Dow was weighed down by a 2.5% decline in Caterpillar shares after the construction equipment maker warned of the effects of tariffs on its business.

Eli Lilly was another big laggard of the session, pulling back about 14% after late-stage trial results of its obesity pill disappointed investors. That's despite the pharmaceutical giant posting second-quarter results that surpassed Wall Street's expectations and raising its full-year outlook.

Stocks initially rallied Thursday after President Donald Trump announced a day earlier that he will impose a 100% tariff on imported semiconductor chips, though not for companies that are "building in the United States." The announcement sent shares of key semiconductor names like Advanced Micro Devices 5.7% higher. The VanEck Semiconductor ETF (SMH) popped more than 1%.

Apple ticked up about 3% after the iPhone maker announced plans to spend an additional $100 billion on U.S. companies and suppliers over the next four years. That's on top of a $500 billion announcement Apple made in February.

"We're going to be putting a very large tariff on chips and semiconductors," Trump said in the Oval Office on Wednesday. "But the good news for companies like Apple is if you're building in the United States or have committed to build, without question, committed to build in the United States, there will be no charge."

The market had been shrugging off the Trump administration's "reciprocal" tariffs, which went into effect Thursday. Additionally, recent economic data, including weekly jobless claims, signaled the U.S. economy may still be in solid shape. This comes after July's weaker-than-expected jobs reading rattled the market last week.

"There's a lot to digest around tariffs and trade right now, and usually when you see a lot of complication around a macro environment that's not immediately negative to the economy or profits, the market … puts it to the side," said Anthony Saglimbene, Ameriprise chief market strategist. "The market is just kind of concentrating on what it can discount right now, which is still a firm economic backdrop and strong earnings."

He said he expects the impact from Trump's tariffs to start showing up in economic data in the fall.

Later Thursday, Trump announced that he has picked Stephen Miran, chair of the Council of Economic Advisors, to serve on the Federal Reserve Board of Governors. He will replace Adriana Kugler following her resignation Friday.

The major averages are on track for a winning week as of Thursday's close. The S&P 500 has gained 1.6% in that period, while the Dow is on pace for a 0.9% advance. The Nasdaq Composite is poised for a 2.9% jump.

Source: CNBC