Stocks held lower on Monday, Aug. 21, as geopolitical tensions and turmoil in the White House again stressed markets. 

The Dow Jones Industrial Average was down 0.26% and the S&P 500 fell 0.21%, while the Nasdaq was off 0.4%.

Worries over North Korea resurfaced over the weekend after the authoritarian nation warned that its army could target the U.S. at anytime, and that Guam, Hawaii nor the mainland won't be able to "dodge the merciless strike." In its official government newspaper, North Korea also said that the United States' upcoming military exercises with South Korea are "reckless behavior driving the situation into the uncontrollable phase of a nuclear war."

Tensions between North Korea and the U.S. had ratcheted up earlier in the month on increasingly aggressive threats between the two countries. President Donald Trump promised "fire and fury like the world has never seen" on Aug. 8, prompting North Korea to announce that it had pinpointed U.S. territory Guam as a possible target for an attack. Tempers eased somewhat in the past week. 

Trump's presidency came under scrutiny again on Friday, Aug. 18, after news broke that chief strategist Steve Bannon had left his position. The New York Times reported that Trump insisted that Bannon resign and the adviser submitted his formal notice on Aug. 7. His departure was delayed by the violence at a right-wing rally in Charlottesville, Virginia, and its aftermath. Bannon has since resumed his position as head of alt-right platform Breitbart News. 

The Secret Service is running out of funds to protect the president and his family, according to an exclusive USA Today report. Secret Service Director Randolph Alles told the newspaper that more than 1,000 agents have hit their federally mandated salary caps after covering the Trump family's business and vacation trips over the months Donald Trump has been in office. Trump has drawn criticism for his near-weekly trips to his properties in New Jersey and Florida, among others, since assuming the office in January. 

Turmoil in and outside of the White House has worried investors keen on seeing progress on Trump's tax-cutting agenda. Stock markets have seen significant increases since the November presidential election on high hopes for business-friendly deregulation and favorable changes to the tax code. Markets sold off last week on worries Trump's agenda had derailed.

"Ever since the election, the broader market has been more upbeat on potential business friendly policy changes given that the President has surrounded himself with staff from the business community," Nomura analysts wrote in a note. "Any material changes to that formula finally caught the equity markets' attention. The risk of losing focus on business includes pivoting to a more populist trade agenda, failing to make reasonable picks for the Federal Reserve and other economic posts, and compromising the ability to formulate a reasonable tax plan."

Trump will deliver a prime-time address on Monday regarding the military's strategy in Afghanistan. In the nationally televised speech, Trump will outline "the path forward" for the U.S. in the long-running conflict. Secretary of Defense James Mattis told Reuters that he is "very comfortable that the strategic process was sufficiently rigorous and did not go in with a pre-set position." Trump met with key cabinet members and top military advisers at Camp David over the weekend to discuss Afghanistan, among other issues.

Financial stocks were among the worst performers on Monday. Bank of America Corp. (BAC) , HSBC Holdings PLC  (HSBC) , Banco Santander S.A. (SAN) , Goldman Sachs Inc. (GS)  and Morgan Stanley (MS) were lower, while the Financial Select Sector SPDR ETF (XLF) declined 0.4%. 

Crude oil prices were lower on Monday in a retreat from last week's gains. Concerns over Organization of Petroleum Exporting Countries' compliance with a production cut agreement also weighed on prices. OPEC and non-OPEC members are set to meet in Vienna on Monday to address a global supply imbalance. Compliance with a previously agreed upon output restrictions reached its lowest level of 2017 in July.

West Texas Intermediate crude was down 1.5% to $47.79 a barrel on Monday. 

Fiat Chrysler Automobiles NV  (FCAU) shares were sharply higher on Monday after a Chinese carmaker confirmed its interest in buying the company. China's Great Wall Motor also indicated that it could be interested in purchasing just the Jeep brand and has approached Fiat to see whether a deal could be negotiated. However, Fiat has said it has not been approached by Great Wall Motor about the Jeep brand. 

French oil company Total SA (TOT) was down slightly on Monday after agreeing to acquire A.P. Moeller-Maersk A/S's oil and gas business. The $4.95 billion deal also sees Total assume $2.5 billion of Maersk Oil's debt. The deal remains subject to shareholder and regulatory approval. It is also a positive sign that the oil industry is beginning to feel more confident in stabilizing oil prices and higher demand. 

The Container Store Group Inc.  (TCS) moved 7% lower on Monday after amending loan agreement terms and reducing its full-year profit guidance. The retail chain anticipates full-year earnings of 27 cents to 40 cents a share, down from a previous target range of 37 cents to 49 cents a share. Analysts anticipated 37 cents. Adjustments to its loan agreement is expected to rack up around $7 million in incremental interest costs. 

Nike Inc. (NKE) fell 3% on a ratings downgrade. Jefferies cut its rating to hold from buy and reduced its price target to $60 from $75 as competition from Adidas AG (ADDYY) intensifies. Nike's growth and margins could be at risk moving ahead as elevated selling, general and administrative expenses occupy near-term funds and marketing campaigns become more important for Nike's ability to "defend its turf" from Adidas, Jefferies said.

Herbalife Ltd. (HLF) increased more than 9% after conducting a self-tender offer to purchase up to $600 million in shares. The vitamin company also said it had held talks with a potential investor on going private. Herbalife said it had terminated these conversations on Aug. 16, but had decided on the self-tender offer to give shareholders "some protection in the event the company is taken private within two years."

Updated from 10:16 a.m. ET, Monday, Aug. 21. 

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