10 things you need to know before the opening bell

Here is what you need to know.

Trump has a short list of Fed candidates. Fed Chair Janet Yellen, National Economic Council Director Gary Cohn, former Fed board governor Kevin Warsh and current governor Jerome Powell are on Trump's short list, according to Bloomberg's Jennifer Jacobs and Saleha Moshin, citing two senior administration officials.

Spain's king weighs in on Catalonia's independence referendum. King Felipe VI criticized Catalan authorities in a rare TV appearance on Tuesday, saying they "have placed themselves outside the law and democracy, they have tried to break the unity of Spain and national sovereignty," according to a translation of the speech by the Financial Times.

Lloyd Blankfein isn't sure what to think about bitcoin. On Tuesday, Blankfein became the latest Wall Street CEO to chime in about the cryptocurrency, tweeting, "Still thinking about #Bitcoin. No conclusion - not endorsing/rejecting. Know that folks also were skeptical when paper money displaced gold."

JPMorgan is the largest US bank by assets and market cap. The bank's deposits grew by $96 billion, or 7.9%, over the past year to $1.31 trillion as of June 30, according to data released this week by the Federal Deposit Insurance Corporation.

The European Union hits Amazon with a huge fine. The European Commission has ordered Amazon to pay €250 million (about $295 million) of unpaid back taxes after discovering an illegal "sweetheart" tax deal in Luxembourg.

Every single Yahoo account was compromised by hackers. All 3 billion user accounts that were active in 2013 were impacted by the security breach, the company, which Verizon acquired in June, said on Tuesday. The company had previously estimated that 1 billion accounts were hacked.

Softbank is taking a big stake in Uber. The Japanese conglomerate will take a stake of up to 17% in Uber, which will IPO by 2019, a person familiar with the matter told Business Insider.

Stock markets around the world are mixed. Hong Kong's Hang Seng (+0.73%) led the gains in Asia and France's CAC (-0.37%) trails in Europe. The S&P 500 is set to open unchanged near 2,534.

Earnings reporting is light. Monsanto and Pepsi release their quarterly results ahead of the opening bell.

US economic data flows. ADP Employment Change will be released at 8:15 a.m. ET before Markit PMI and ISM non-manufacturing are announced 9:45 a.m. ET and 10 a.m. ET, respectively. The US 10-year yield is down 1 basis point at 2.31%.