What you need to know on Wall Street today

KCNA via Reuters

North Korean leader Kim Jong Un guides a target-striking contest of the special operation forces of the Korean People's Army (KPA) to occupy islands in this undated picture provided by KCNA in Pyongyang on August 25, 2017.

North Korea has once again ratcheted up geopolitical tensions with its most recent missile test, and the effects are being felt in stock markets worldwide.

European and Asian markets dropped, while US markets opened in the red before rebounding. You can see a map of global stock markets right here. Gold hit its highest level this year, meanwhile, and the dollar tumbled to its lowest level since January 2015. US-China relations could see a "real deterioration" after North Korea's missile launch.

Relief efforts for those affected by Hurricane Harvey are underway, even as devastating flooding continues in Texas, and the storm moves on to Louisiana. Here's the latest:

• Harvey pummels Texas with "catastrophic," "unprecedented" flooding and turns its eye on Louisiana
• Here's how to donate to the Red Cross and Salvation Army to help Hurricane Harvey victims in Texas
• Hurricane Harvey throws another wrinkle into Congress' wild "budget brawl"
• There's a reason economic measures are no good at capturing the likely damage from Hurricane Harvey
• MORGAN STANLEY: Here are the insurers that stand to lose the most from Hurricane Harvey

In markets news, Wall Street is divided over the future of banks. And a former manager at Target became a millionaire using one of Wall Street's favorite trades.

In deal news, airline-equipment giant United Technologies is reportedly closing in on a more than $20 billion deal. Wall Street investment banks are set to make as much as $90 million in fees from Gilead Sciences' acquisition of Kite Pharma. Here's why Gilead broke its dealmaking hiatus and splurged $12 billion on a cancer treatment.

In another sign of retail pain, Best Buy tumbled after its CEO said strong sales are not a "new normal," and Finish Line crashed after slashing its forecast for profits. Nike and Under Armour also took a hit.