10 things you need to know before the opening bell

Moody's downgrades China for the first time since 1989. The ratings agency cut its China rating to A1 from Aa3, saying it "expects that economy-wide leverage will increase further over the coming years."

Iron ore got crushed. The commodity tumbled by more than 6% after Moody's downgraded China.

Bitcoin roars to a new high. The cryptocurrency trades up $109, or 4.9%, at $2,325 a coin. Wednesday marks the first time bitcoin has cleared the $2,300 level.

Fed's Harker says a June rate hike is on the table. Speaking with reporters, the Philadelphia Fed president, Patrick Harker, said a June interest-rate hike was a "distinct possibility."

Glencore is trying to get into America's agriculture market. Glencore, one of the world's largest commodities traders, is reportedly making a run at Bunge, but there's no assurance a deal will be reached, The Wall Street Journal says.

The owner of Corona reportedly made an offer for the owner of Jack Daniels. Constellation Brands made an undisclosed offer for Brown-Forman but was rejected, CNBC reports.

Softbank is taking a big stake in Nvidia. The Japanese tech giant has invested $4 billion in the chipmaker, good for about a 4.9% stake, Bloomberg says.

Stock markets around the world are higher. Japan's Nikkei (+0.7%) paced the advance in Asia, and Britain's FTSE (+0.2%) is out front in Europe. The S&P 500 is set to open slightly higher near 2,400.

Earnings reports flow. Lowe's and Tiffany report ahead of the opening bell, while HP releases its quarterly results after markets close.

US economic data remains light. The FHFA House Price Index and existing-home sales will cross the wires at 9 a.m. ET and 10 a.m. ET. The minutes from the May Federal Open Market Committee meeting are due out at 2 p.m. ET. The US 10-year yield is down by 1 basis point at 2.27%.