Global stocks were mixed Wednesday as markets weighed lingering worries about the Iran-Israel conflict while Nvidia surged to a fresh all-time high on bullishness over artificial intelligence.

Analysts cited not only concerns that the ceasefire between Iran and Israel could break down, but leaked US intelligence that said strikes had set back Tehran's nuclear program by just a few months.

"Maybe the US bombardment didn't destroy the Iran nuclear program," said Jack Ablin of Cresset Capital Management, adding that that revelations about the Iran nuclear program suggested the Iran story is not a "new chapter."

The S&P 500 finished a choppy day flat, while the Dow edged lower and the Nasdaq advanced.

"Investors are sort of catching their breath, since we had a very strong move on Monday and Tuesday," said Sam Stovall, chief investment officer at CFRA Research. "Nvidia's on everyone lips today."

The chip company shot up 4.3 percent to $154.31, giving it a market valuation of around $3.76 trillion -- more valuable than Microsoft, Apple and other tech giants.

The rise came as CEO Jensen Huang presented the company's latest technologies at Nvidia's annual meeting.

Asian stock markets had closed higher earlier on Wednesday following rallies on Wall Street and in Europe the day before. But European stocks fell in Wednesday's session.

Oil prices, meanwhile advanced after two days of heavy losses following a US crude inventory report that showed a bigger than expected drawdown in inventory.

The dollar continued to slide against the euro, with fewer benefits from the flight to safety due to unrest in the Middle East.

While the Israel-Iran conflict has dominated global attention in recent days, markets are also shifting attention back to trade. 

Shares of FedEx fell 3.3 percent after the shipping company did not provide a full-year forecast, citing uncertainty about the global trade outlook and tariffs.

Dozens of countries are locked in negotiations with Washington to clinch some sort of trade deal to mitigate the impact of US tariffs. 

Only Britain has been reached a deal, although Beijing and Washington have agreed to lower tariffs from the highest rates they imposed upon one another.

Key figures at around 2040 GMT

Brent North Sea Crude: UP 0.8 percent at $67.68 per barrel

West Texas Intermediate: UP 0.9 percent at $64.92 per barrel

New York - Dow: DOWN 0.3 percent at 42,982.43 (close)

New York - S&P 500: FLAT at 6,092.16 (close)

New York - Nasdaq Composite: UP 0.3 percent at 19,973.55 (close)

London - FTSE 100: DOWN 0.5 percent at 8,718.75 (close)

Paris - CAC 40: DOWN 0.8 percent at 7,558.16 (close) 

Frankfurt - DAX: DOWN 0.6 percent at 23,498.33 (close)

Tokyo - Nikkei 225: UP 0.4 percent at 38,942.07 (close)

Hong Kong - Hang Seng Index: UP 1.2 percent at 24,474.67 (close)

Shanghai - Composite: UP 1.0 percent at 3,455.97 (close)

Euro/dollar: UP at $1.1656 from $1.1609 on Tuesday

Pound/dollar: UP at $1.3664 from $1.3615

Dollar/yen: UP at 145.32 yen from 144.94 yen

Euro/pound: DOWN at 85.26 from 85.27 pence