U.S. stocks lacked direction in Friday's trading, amid new U.S. tariffs and rising risks of a federal government shutdown. 

The S&P 500 index hugged the flatline, and the Nasdaq Composite decreased 0.1% as investors reviewed the latest update on the Fed's inflation gauge. 

The federal government is likely to face its first shutdown in five years as lawmakers from both parties dig in their heels and fail to strike a compromise on healthcare spending.

The looming shutdown could stop or delay payments for social security, federal contractors, and as many as two million federal employees. 

The U.S. president threatened to impose additional tariffs on trucks, furniture, and pharmaceuticals, which could lead to more disruptions in global supply chains and support elevated inflation at home.

Trump threatened to impose tariffs of as much as 100% on branded or patented drugs, 25% on heavy-duty trucks, and 30% on upholstered furniture.

The latest tariff salvo adds more confusion to the so-called trade agreements and imports from countries deemed as most favored nations. 

The Trump administration's constant tinkering of trade policy, random announcements, pullbacks, withdrawals, and reimpositions have shaken the faith of foreign investors.

U.S. Stock Movers 

Costco Wholesale Corp. decreased 1% to $935.49, and the membership warehouse club operator reported solid quarterly results. 

However, the retailer's same-store sales growth slowed for the second quarter in a row. 

Revenue in the fiscal fourth quarter increased to $86.2 billion from $79.7 billion, net income advanced to $2.61 billion from $2.35 billion, and diluted earnings per share rose to $5.87 from $5.21 a year ago. 

Same-store sales, excluding store openings and closures, foreign exchange adjustments, and gasoline sales, increased 6.4%, and e-commerce sales surged 13.5% from a year ago, respectively. 

Membership fee income soared 14% from a year ago in the quarter, as the company attracted younger and paying customers. 

Concentrix Corp. plunged 19.5% to $44.24 after the business process outsourcing company reported weaker-than-expected quarterly results and the service company tightened its outlook.