• The major stock indexes saw modest gains to start June.
• The CEO of Campbell's said people are cooking at home at the highest levels since early 2020.
• Steph Curry talked to CNBC about his business plans for a world after basketball.

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

1. On the board

The major stock indexes posted modest gains Monday to start the month, as the S&P 500 rose 0.41%, the Nasdaq Composite added 0.67%, and the Dow Jones Industrial Average eked out a 35.41 point gain, or 0.08%. Investors mostly shook off increasing global tensions over trade, but steel stocks surged after President Donald Trump said he would double steel tariffs to 50%. Cleveland-Cliffs soared 23%, while Steel Dynamics and Nucor both jumped 10%. Follow live market updates.

2. Home chef

The CEO of Campbell's said people are cooking at home at the highest levels since early 2020, the start of the pandemic. Campbell's CEO Mick Beekhuizen said that trend has played out among all income brackets in the meals and beverages category, giving the latest sign that consumers are potentially being cautious on spending amid economic concerns. That could mean people are eating out less, which would be bad news for gross domestic product readings that heavily rely on consumer spending. Beekhuizen's remarks came as the company beat Wall Street expectations in its fiscal third quarter.

3. Office zone press

For the first time in 25 years, more office space is being removed than added, as office conversions and demolitions will exceed new construction, according to new data from real estate services and investment firm CBRE Group. Office vacancies soared to a record high at 19% and are still lingering around that mark thanks to a growing remote-work culture and a shift in office attendance since the start of the pandemic. The market is starting to show some signs of recovery, but developers are planning to convert an additional 85 million square feet of office space in the next few years.

4. New round

Neuralink, Elon Musk's brain tech startup, said it has closed a $650 million funding round led by ARK Invest, Founders Fund, Sequoia Capital, Thrive Capital, Lightspeed Venture Partners and others. The company is building a brain-computer interface, or BCI, which is able to translate brain signals into commands that can control technology outside the body and aims to help patients with severe paralysis. Paradromics, which is working on similar technology, said on Monday it had successfully implanted its BCI in a human for the first time.  

5. What's cooking?

Four-time NBA champion Stephen Curry isn't ready to retire from basketball yet, but he's thinking ahead to what his business will look like off the court. Curry is already the CEO of Thirty Ink, a mini-conglomerate of businesses including multimedia company Unanimous Media, bourbon brand Gentleman's Cut and marketing consultancy 7k. He's also president of Under Armour's Curry Brand, which he said changed the way he thought about his off-court business. But he told CNBC that after the NBA, he's considering doing more and is eyeing careers in broadcasting, team ownership and professional golf. Curry spoke to CNBC Sport as part of the TV production "Curry Inc.: The Business of Stephen Curry," which is airing on CNBC on Wednesday at 9 p.m. ET.

— CNBC's Sean Conlon, Alex Harring, Diana Olick, Ashley Capoot, Alex Sherman and Jessica Golden contributed to this report.