U.S. markets showed mixed results early Tuesday as technology stocks retreated from some of their gains posted the previous session.

Futures for the S&P 500 slipped 0.2% while futures for the Dow Jones Industrial Average edged up 0.3%. Nasdaq futures declined 1%.

Semiconductor and memory-related technology stocks that supported markets on Monday traded lower in premarket action Tuesday.

In Asia, chipmaker Samsung Electronics fell 7.7% even as operating income surged 19-fold in the latest quarter and revenue more than doubled.

Artificial intelligence stocks fluctuated amid bubble concerns, raising questions over whether spending on AI chips and data centers can generate enough productivity and profit gains to justify the investments.

"The first proper AI stress test may not have arrived with weak demand, a capex warning, or some sudden crack in the data center story. It may have arrived with Samsung posting an extraordinary quarter and the stock falling anyway," Stephen Innes of SPI Asset Management said in a commentary.

U.S. chipmaker Broadcom, which helped lift markets Monday with a 3.7% gain, gave back most of those advances overnight and slid 2.8% before the opening bell. Micron, Marvell Technology and Intel each fell between 4% and 6% in early trading.

Western Digital, a data storage firm whose shares have tripled this year on the AI wave, dropped 7% ahead of the opening bell.

SpaceX, which owns xAI, fell less than 1% ahead of its debut on the Nasdaq 100 index. That inclusion will force funds like the QQQ exchange-traded fund, which mimic the index, to buy SpaceX shares themselves.

At midday in Europe, Germany's DAX shed 0.6%, the CAC 40 in Paris climbed 0.3% as did Britain's FTSE 100.

Asian share markets retreated, with South Korea's Kospi closing 4.9% lower at 7,656.31 after dropping as much as 8% earlier in the day.

Tokyo's Nikkei 225 declined 2.1% to 68,256.96. Computer chipmaker Tokyo Electron lost 3.9% and chipmaker Kioxia Holdings shed 11.3%.

The Hang Seng in Hong Kong declined 0.5% to 23,496.98, while the Shanghai Composite index gave up 1.3% to 3,990.24. Taiwan's Taiex lost 2.3%.

In Australia, the S&P/ASX 200 declined 0.3% to 8,803.90 and India's Sensex shed 0.1%.

In oil markets, the price of a barrel of Brent crude, the international standard, rose 69 cents to $72.68 a barrel. That is close to where it stood before the United States and Israel attacked Iran in late February, sending prices spiking.

The stability of supplies remains uncertain. A tanker traveling off the coast of Oman in the Strait of Hormuz caught on fire early Tuesday morning after being struck by a projectile, the British military said.

The attack was the latest targeting a vessel moving through the narrow mouth of the Persian Gulf, through which a fifth of all oil and natural gas traded once passed in peacetime. Iranian state television said the liquefied natural gas tanker came under attack after ignoring warnings but did not directly claim the assault.

U.S. benchmark crude added 56 cents to $69.11 a barrel.