• Consumer confidence saw its biggest one-month decline in more than three years.
• The U.S. Department of Justice sued Visa.
• Caroline Ellison, the star witness in the prosecution of her former boyfriend and FTX founder Sam Bankman-Fried, was sentenced to two years in prison.

Here are five key things investors need to know to start the trading day:

1. Another one

The S&P 500 and the Dow Jones Industrial Average both hit record highs on Tuesday as the broad market index added 0.25% and the 30-stock Dow rose 83.57 points, or 0.20%. The Nasdaq Composite climbed 0.56% as artificial intelligence darling Nvidia rose nearly 4% after a regulatory filing showed CEO Jensen Huang may be done selling shares after hitting a prearranged plan limit. Follow live market updates.

2. Faltering confidence

Consumers have a slightly more pessimistic view of the economy. The Conference Board's consumer confidence saw its biggest one-month decline in more than three years, falling to 98.7. That's down from 105.6 in August and a bigger drop than the 104 reading economists polled by Dow Jones expected. The last time the confidence index dropped by more was in August 2021, as inflation was just beginning to climb. Respondents were most concerned with jobs and inflation, with fewer saying jobs are plentiful.

3. Visa charges

Visa got hit with a different kind of charge on Tuesday. The U.S. Department of Justice sued the world's biggest payments network and accused it of propping up an illegal debit network monopoly that affects the price of "nearly everything." "We allege that Visa has unlawfully amassed the power to extract fees that far exceed what it could charge in a competitive market," Attorney General Merrick Garland said in a DOJ release. The DOJ also accused the company of imposing "exclusionary" agreements on partners and hurting innovation at upstart firms. Visa's stock closed more than 5% lower for the day.

4. Drug prices

Senators grilled Novo Nordisk CEO Lars Fruergaard Jørgensen at a hearing on Tuesday over the high prices of the company's blockbuster injections. Jørgensen did not explicitly promise to cut the prices of weight loss drug Wegovy and diabetes treatment Ozempic, but said he wants to work with Congress on policy solutions that will address the "structural issues" that drive up prescription drug costs. He also said he would work with pharmacy benefit managers, the middlemen who negotiate drug rebates with manufacturers on behalf of insurers. Sen. Bernie Sanders, the Vermont independent who chairs the Senate panel that questioned Jørgensen, argued that Novo Nordisk charges Americans much higher prices for Wegovy and Ozempic than it does for patients in other countries.

5. Star witness sentenced

A judge in New York federal court sentenced Caroline Ellison — the star witness in the prosecution of her former boyfriend and FTX founder Sam Bankman-Fried — to two years in prison, saying he couldn't agree to a "literal get-out-of-jail-free card." Judge Lewis Kaplan also ordered her to forfeit $11 billion for her role in the massive fraud and conspiracy that led to the downfall of the cryptocurrency exchange. The federal Probation Department had recommended no time behind bars for Ellison, who reached a plea deal with prosecutors in December 2022, a month after FTX spiraled into bankruptcy. Kaplan praised Ellison for her cooperation in the case but said her criminal sentence was necessary to deter other bad actors.

— CNBC's Brian Evans, Jeff Cox, Hugh Son, Annika Kim Constantino, MacKenzie Sigalos, Dan Mangan and Dawn Giel contributed to this report.