US benchmark equity indexes ended lowered Tuesday as fresh tariff news fueled market volatility and dented sentiment.

* The Trump administration is moving forward with an additional 50% tariff on China that brings the total rate of levies on the country to 104%, a White House official told CNBC. The new rate goes into effect at 12:01 a.m. ET Wednesday.

* Small business optimism in the US deteriorated more than expected in March as owners scaled back expectations on sales growth, a survey by the National Federation of Independent Business showed.

* "The implementation of new policy priorities has heightened the level of uncertainty among small business owners over the past few months," said NFIB Chief Economist Bill Dunkelberg. "Small business owners have scaled back expectations on sales growth as they better understand how these rearrangements might impact them."

* May West Texas Intermediate crude oil closed down $2.44 to settle at $58.26 per barrel, while June Brent crude, the global benchmark, was last seen down $2.57 to $61.60 as the tariff battle between the US and China heated up.

* Humana (HUM) shares were up almost 10%, followed by CVS Health (CVS) and UnitedHealth Group (UNH) at 5% and 4.7%, respectively. The US Centers for Medicare and Medicaid Services said late Monday it will increase payment rates for Medicare insurers next year.

* The EU will soon issue decisions on whether Apple (AAPL) and Meta Platforms (META) failed to comply with tech competition rules, media outlets reported Tuesday, citing antitrust chief Teresa Ribera. Apple shares were down 6.6% while Meta fell 2.4%.