NEW YORK (Reuters) - A gauge of global stock markets rallied along with U.S. Treasury yields on Wednesday as optimism abounded for a trade thaw between the United States and China while sterling bounced on indications UK Prime Minister Theresa May would survive a no-confidence vote.

Traders work on the floor of the New York Stock Exchange (NYSE) in New York, U.S., December 11, 2018. REUTERS/Brendan McDermid

U.S. Treasury yields advanced in tandem with Wall Street’s gains after U.S. President Donald Trump said trade talks with China were progressing with discussions under way by telephone and more meetings likely among officials of both countries.

In an interview with Reuters on Tuesday, Trump also said he would intervene in the Justice Department’s case against a top executive at China’s Huawei Technologies Co Ltd if it served national security interests or helped to close a trade deal.

China made its first major U.S. soybean purchases in more than six months on Wednesday, two U.S. traders said, and its first since Trump and his Chinese counterpart Xi Jinping struck a trade war truce in early December.

But after a spate of dizzying volatility in the past few days, there was some wariness about whether gains would hold.

“The market just kind of gets whipsawed every time you get a headline,” said Tom Hainlin, global investment strategist at Ascent Private Capital Management in Minneapolis.

“These are policies and concerns that don’t have a lot of informational arbitrage - it is hard to know exactly where the U.S.-China trade is going to go.

The Dow Jones Industrial Average rose 158.8 points, or 0.65 percent, to 24,529.04, the S&P 500 gained 14.45 points, or 0.55 percent, to 2,651.23 and the Nasdaq Composite added 66.48 points, or 0.95 percent, to 7,098.31.

Still, U.S. equities finished well off their session highs and traders were not convinced the market was ready for a sustained move upward after two-straight days of gains.

“The risk right now is to the downside still, even though we had this reversal,” said Gordon Charlop, managing director at Rosenblatt Securities in New York.

The pan-European STOXX 600 index rose 1.69 percent to give the index its best two-day performance in two-and-1/2 years and MSCI’s gauge of stocks across the globe gained 1.10 percent.

The British pound sterling jumped off 20-month lows as Prime Minister May vowed to fight a challenge to her leadership, saying a change could jeopardize Britain’s divorce from the European Union.

May won a vote of confidence in her leadership right as U.S. markets closed for the session.

Sterling was last trading at $1.261, up 1.01 percent on the day.

The dollar index fell 0.33 percent, with the euro up 0.46 percent to $1.1366.

Benchmark 10-year notes fell 8/32 in price to yield 2.9096 percent, from 2.881 percent late on Tuesday.