Axios

South Korea plans to build and launch its first nuclear-powered submarine by the mid-2030s, a move in part meant to counter the growing arsenal of its neighbor, North Korea.

Why it matters: This massive undertaking will test the country's shipbuilding sector — often lauded in the U.S. — as well as international nonproliferation obligations.

• If successful, it could reshape the security status quo in Asia. Only a handful of countries today operate nuclear-powered subs.

Crude oil prices dropped about $5 per barrel Sunday evening in the first major trading since the emergence of rough and tentative outlines of a deal to end the U.S.-Iran conflict.

Why it matters: The throttling of the Strait of Hormuz is raising energy costs and weighing down economies worldwide — including the U.S., where average pump prices are about $1.50-per-gallon above pre-war levels.

Open-source AI firm Reflection AI is partnering with the Department of Energy to help power the Genesis Mission, a federal scientific research initiative, per an announcement shared exclusively with Axios.

Why it matters: The partnership is a big advancement for a company that's trying to get the U.S. to embrace open-source models.

Fusion energy — tapping the power of the stars — is on the cusp of getting new federal rules.

Why it matters: Regulators increasingly view fusion as fundamentally safer than nuclear fission, helping to pave the way for a substantially simpler permitting process than the one faced by conventional nuclear plants.

A record number of Americans will hit the road over Memorial Day weekend — and they'll pay an average of $1.34 more per gallon at the pump compared to a year ago.

Why it matters: Holiday car trips are proving to be resilient, even as President Trump's war with Iran pushes gas prices sharply higher.

Stellantis plans to add affordable entry-level cars and high-performance trucks to its U.S. showrooms over the next five years as part of a 60 billion euros ($70 billion) global turnaround plan.

Why it matters: Expanding into new market segments is a key aspect of Stellantis' strategy reboot as it tries to reinvigorate its 14 brands and strengthen its financial performance in the hyper-competitive auto industry.

This year's Atlantic hurricane season is expected to be below average in storm activity for the first time in more than a decade, NOAA meteorologists said Thursday in their annual forecast.

Why it matters: Residents should still take the season seriously and prepare now, officials stressed.

• "It's very important to understand that it only takes one," NOAA administrator Neil Jacobs told reporters.

Walmart's growth beyond its stores continued in the first quarter, driven by advertising, e-commerce and memberships.

Why it matters: The nation's largest retailer is increasingly making money from the services built around shopping — not just the products on its shelves.

The Environmental Protection Agency is easing Biden-era rules for industries to manage and phase out powerful planet-warming gases used in air conditioning and refrigeration, a White House official said.

Why it matters: Officials claim the plan — which President Trump will unveil at the White House Thursday — will help temper grocery prices.

Automakers and suppliers in search of a lucrative side hustle are dabbling in AI, energy and defense as a way to offset stagnant growth in vehicle sales.

Why it matters: Carmakers have tried the diversification game before — but today's economic and technological shifts may give those efforts more staying power.