Warren Buffett, the billionaire chief executive officer and chairman of Berkshire Hathaway Inc, said Tuesday that an exit by Greece from the euro zone could be constructive for the region.

Wall street analysts may be inadequately accounting for the dollar’s sharp rise in the first quarter, setting up a scenario in which some multinationals may miss already low consensus estimates - and their shares sell off as a result.

U.S. stocks ended down on Tuesday in a retreat from the previous session's sharp rally as energy shares declined and the dollar edged up, but the S&P 500 and Nasdaq registered their ninth straight quarterly rise.

U.S. stock fell on Tuesday in a modest retreat from the previous session's sharp rally, though major indexes remained on track for a positive first quarter and the S&P 500 was set for its ninth straight quarterly rise.

Hedge fund mogul William Ackman, who has spent more than two years accusing Herbalife Ltd (HLF.N) of running a pyramid scheme, said on Monday that shutting down the company is "one of the most important things" he can do.

U.S. stocks climbed more than 1 percent on Monday, rebounding from a sharp decline last week, helped by deal activity in healthcare and a bounce in energy shares.

The euro fell on Monday, hurt by uncertainty over whether Greece and its international creditors will be able to strike a deal that will help Athens secure funding before it runs out of money by April 20.

Billionaire financier George Soros is ready to invest $1 billion in Ukraine, if Western countries help private investment there. He also put the odds of Greece leaving the euro at a third, in an interview with Austrian newspaper Der Standard.

Asian stock markets rose on Monday, with China stocks nearing a seven-year peak on hopes for more infrastructure spending and policy stimulus, while oil prices suffered further from excess supply.

Goldman Sachs became the top commodities bank last year, overtaking rival JP Morgan, a consultancy said on Friday.