10 things you need to know before the opening bell

Here is what you need to know.

Charter Communications is buying Time Warner for $55 billion.The two sides announced a $195.71 per share cash and stock deal that values Time Warner at mores than $55 billion. The deal comes at a 14% premium to Time Warner's closing price on Friday, and is between the second (Time Warner) and fourth (Charter Communications) largest cable operators in the US.

Fiat Chrysler's made a bid for General Motors, but was rejected. The New York Times reports Fiat Chrysler CEO Sergio Marchionne proposed a takeover to General Motors CEO Mary Barra in March, but was quickly turned down. Marchionne tried to sell the idea that a merger between the two companies would result in billions of dollars of savings while creating an automotive behemoth.

Twitter tried to buy Flipboard. Re/code's Kara Swisher reports Twitter tried to buy magazine-style article curation app Flipboard in a deal that would value the company at around $1 billion. It remains unclear as the Twitter's motive behind the deal, but Re/code speculates Twitter may be interested in part because of Flipboard's experienced product team. The talks have reportedly stalled.

Amazon changed its tax practices in Europe.The on-line retailer is now recording revenues in each individual European country instead of everything flow through Luxembourg. The Wall Street Journal reports, "Depending on how the company allocates costs, it could significantly boost the firm's tax bill in many EU countries. It could also put pressure on other companies to do the same."

Samsung is merging two key units. AFP says, "The all stock deal, approved by the boards of both companies would see Samsung's de facto holding company Cheil Industries -- which has interests from fashion to theme parks -- acquire general trade and construction affiliate Samsung C&T." Cheil will offer 0.35 shares for each Samsung C&T share. The new company will be go by the name Samsung C&T.

The IMF says China's yuan is no longer undervalued. According to the International Monetary Fund,"Our assessment now is that the substantial real effective appreciation over the past year has brought the exchange rate to a level that is no longer undervalued." The IMF also announced it expects China to grow 6.8% versus last year with inflation of around 1.5%. China's yuan is was little changed at 6.2037.

A deal between Greece and its creditors remains elusive. Talks between Greece's government and its creditors continue to drag on. The government has said it won't be able to make its June 5 payment to the IMF. Greece's finance minister, Yannis Varoufakis, believes the government has done all it can do, and it is now up to its creditors to make something happen. Greece's 2-year yield is higher by 256 basis points at 25.19%.

Spain's anti-austerity Podemos Party took a beating in local elections. Reuters reports Prime Minister Mariano Rajoy's party won in 9 of 13 regions, but surrendered 2.5 million votes from the 2011 local elections and 5 million votes from the 2011 general election. "It's the beginning of the end of Mariano Rajoy as Prime Minister," noted socialist leader Pedro Sanchez. Spain's 10-year yield is up 3 basis points at 1.83%.

Global stock markets trade mixed. China's Shanghai Composite (+2.0%) paced the advance in Asia while Italy's MIB (+0.7%) leads the way in Europe. Germany's DAX (-0.5%) is a notable laggard.S&P 500 futures are down 4.00 points at 2120.50.

US economic data is heavy. Durable orders are due out at 8:30 a.m. ET while Case-Shiller 20-city Index and FHFA Housing Price Index are scheduled for 9:00 a.m. ET. Data concludes for the day at 10 a.m. ET as new home sales and consumer confidence cross the wires. The US Dollar Index is higher by 1% at 96.96.