This report is from today's CNBC Daily Open, our international markets newsletter. CNBC Daily Open brings investors up to speed on everything they need to know, no matter where they are. Like what you see? You can subscribe here.

What you need to know today

Tech rebound
The S&P 500 posted its biggest gain since June 5, recovering from its worst weekly slide since April, as tech stocks rebounded led by Nvidia. The Nasdaq Composite rose 1.58% to close above 18,000, while the Dow Jones Industrial Average advanced 127 points. Small-cap stocks also performed well, with the Russell 2000 rising 1.7%. The yield on the 10-year Treasury inched higher ahead of economic data later in the week. U.S. oil prices slipped.

CrowdStrike tumbles
Republican representatives have called on CrowdStrike CEO George Kurtz to testify before the House Committee on Homeland Security, following a faulty software update that crashed millions of Microsoft Windows devices. Rep. Mark Green and Rep. Andrew Garbarino said the incident was a "warning about the national security risks associated with network dependency," according to a letter issued on Monday. CrowdStrike shares slumped 13%. Reeling from the IT glitch, Delta Air Lines canceled 900 flights — 23% of its mainline operations — by Monday evening.

Buffett trims stake
Warren Buffett's Berkshire Hathaway has sold $1.5 billion worth of Bank of America shares, marking the first reduction in its stake since 2019. The move comes after the bank's stock rallied 27.4% this year, reaching its highest level since March 2022. Despite the sale, Bank of America remains Berkshire's second-largest holding after Apple, and Berkshire remains the bank's largest shareholder with a 10.8% stake.

Vote of confidence
Boeing secured an order for 40 wide-body jets from Korean Air at the Farnborough Airshow. The order includes 20 Boeing 777X planes — which are yet to be certified — and the same number of 787-10 Dreamliners, with an option for 10 more Dreamliners. The deal marks a significant win for Boeing, which has faced recent challenges with production delays and safety concerns. "If I wasn't assured, I would not have ordered it," Korean Air CEO Walter Cho said. "I know Boeing will pull through whatever it is they're going through right now, and I have full confidence in Boeing." 

NBA rights
Warner Bros. Discovery has exercised its right to match a $1.8 billion per year deal between the National Basketball Association and Amazon Prime Video for a package of games. The move allows Warner Bros. to retain some of its NBA broadcasting rights. However, the NBA may not want Warner Bros. as a media rights partner and could reject the company's matching rights, which could lead to a legal tussle. 

[PRO] Market uncertainty
Wall Street had anticipated a Trump victory following President Joe Biden's poor June debate performance. However, Biden's endorsement of Vice President Kamala Harris has complicated those expectations. This is what investors are saying. 

The bottom line

Wall Street largely took Biden's decision to end his stalled reelection campaign in its stride. His endorsement of Harris prompted donors, including Disney heiress Abigail Disney, to support her candidature. Harris and the Democratic Party raised $100 million in online donations after Biden's exit.

Amid discussions about the potential resurgence of the "Trump trade" following an attempt on former President Donald Trump's life and the increasing likelihood of him securing a second term, seasoned investors advised retail investors to avoid making hasty changes to their portfolios.

"Do not make portfolio changes based on what you think the election is going to bring three and a half months before the election," Jim Lebenthal, chief equity strategist at Cerity Partners, told CNBC. "In the last month, we've had convictions, we've had the very unfortunate assassination attempt, we've had the presumptive nominee of the Democratic Party drop out. There will probably, highly likely, be more changes to come."

You can read more of CNBC's coverage here:

• Here's what a Harris administration could mean for your wallet.
• As Harris seeks to win over doubters, analysts explain what to watch
• Biden dropping out adds more uncertainty to markets. What investors are saying
• How Biden's unpopular economic record could be a challenge for Harris

Despite political uncertainty, Strategas' Dan Clifton noted the S&P 500 has risen 6% in seven weeks, attributing this to higher liquidity. 

"There are limits to how much the political events are going to have impacts on the broader equity market," he said on CNBC's "The Exchange." "So there's a cushion to digest some of this political uncertainty."

Earnings reports and central bank policies remain top priorities for Wall Street. The market is pricing in a more than 92% chance that the Federal Reserve will cut interest rates during its September meeting.

The Fed's preferred inflation gauge, core PCE price index, releases Friday, and will offer hints on the central bank's monetary policy rate cut path.

Before the economic data, automakers start rolling out their earnings. CNBC's Michael Wayland has more on what to expect and why GM is set to be the standout performer among traditional automakers. And CNBC's Lora Kolodny writes Tesla's earnings are due today and investors want a robotaxi update.

— CNBC's Samantha Subin, Hakyung Kim, Lisa Kailai Han, Ashley Capoot, Sarah Min, Alex Sherman, Kate Rogers, Yun Li and Leslie Josephs contributed to this report.