US stocks showed a mixed performance during Thursday's midday session, with the Dow Jones Industrial Average climbing to a new all-time high. Chip stocks faced selling pressure following a disappointing report from Broadcom. Investors continued to monitor developments in the Middle East.

The Dow Jones Industrial Average advanced by 859.90 points, or 1.70%, reaching 51,546.97. The Nasdaq Composite fell by 91.83 points, or 0.34%, to 26,762.15. The S&P 500 gained 12.99 points, or 0.17%, closing the midday session at 7,566.67.

Chipmaker Broadcom Inc saw its shares drop sharply by 13% after reporting second-quarter revenue that fell short of expectations. Cybersecurity stock CrowdStrike Holdings Inc also declined by 10% after issuing a soft revenue forecast for the second quarter.

Semiconductor stocks, which had recently led the market's rally to record levels, experienced broad declines. The VanEck Semiconductor ETF was down more than 3% in pre-market trading. Shares of Arm Holdings plc, Micron Technology Inc, and Marvell Technology Inc each fell by approximately 6%.

US stocks closed lower on Wednesday as escalating tensions in the Middle East pressured the market. Military actions between the US and Iran intensified. Iran targeted Kuwait International Airport earlier on Wednesday; this followed a statement from US Central Command the previous day that it had successfully intercepted multiple Iranian ballistic missiles and drones and conducted a "defensive strike" on Qeshm Island in the Persian Gulf. The Command stated this was in response to what it called an "attempted attack" by Tehran.

For the week, the S&P 500, which had risen for nine consecutive weeks prior, is poised to record a loss. However, Keith Lerner, Co-Chief Investment Officer and Chief Market Strategist at Truist Wealth, noted that a pullback is normal after such a strong advance.

"I just think the market is due for a breather. We've had a big move. The fundamentals are sound. The bull market still deserves the benefit of the doubt, but markets often take two steps forward and one step back. We've taken three steps forward, so we could at least take a half-step back, or at least see some sideways consolidation," Lerner said.

The US Labor Department reported on Thursday that initial jobless claims for the week ending May 30 totaled 225,000. This was an increase of 13,000 from the prior week and exceeded the Dow Jones consensus estimate of 215,000. This figure marks the highest level of claims since the week of February 7.

In other economic data, figures from the Bureau of Labor Statistics showed first-quarter productivity increased by 0.3%, below the expected 0.5% rise. Meanwhile, unit labor costs rose by 1.8%, which was lower than the anticipated 2.4% increase.