Global Markets Slip as Iran Sanctions Meet a Technology Selloff

Global markets showed a cautious response on Monday, August 24, after Treasury Secretary Scott Bessent announced “Operation Economic Outcast,” a campaign designed to increase pressure on Iran and businesses that support its financial and commercial networks. The session’s most important signal was that technology weakness—not an immediate oil shock—dominated trading. The S&P 500 fell 0.28% and the Nasdaq dropped 0.76%, while oil prices declined more than $2 a barrel. 1718

What Operation Economic Outcast targeted

The administration described the campaign as an effort to sever Iran’s economic links and warn companies and countries that continued dealings with Tehran could threaten their access to the U.S. financial system. 125

The reported target areas included:

• digital assets;
• technology;
• gold;
• aviation; and
• shipping. 6710

The campaign was framed as an expansion of secondary-sanctions pressure. However, the initial announcement was also described as a “warning shot,” with the supplied reporting noting that it stopped short of immediately penalizing major financial institutions in countries involved in Iran-linked trade. 512

How major indexes moved

Monday’s closing moves were uneven across regions:

Index	Close	Move
KOSPI	6,696.96	-3.12% 14
Hang Seng	25,517.33	-1.89% 14
Nikkei 225	65,528.09	-0.74% 44
Shanghai Composite	3,882.01	-0.59% 43
Sensex	77,369.11	-0.22% 45
Nifty 50	24,219.05	-0.14% 45
S&P/ASX 200	9,163.30	+0.66% 35
DAX	26,106.60	-0.11% 33
FTSE 100	10,854.32	+0.35% 31

European equities were broadly steady: the pan-European STOXX 600 finished unchanged, with the DAX slightly lower and the FTSE 100 higher. 192831

Why South Korea and Hong Kong fell hardest

The sharpest declines were concentrated in markets with substantial technology and semiconductor exposure. The KOSPI dropped 3.12% as investors reduced risk in chip stocks ahead of Nvidia’s earnings, making South Korea particularly sensitive to the week’s AI and semiconductor trade. 2351

Hong Kong’s Hang Seng fell 1.89%. Its technology and China-sensitive exposure left it vulnerable to the same global risk reduction, while investors also weighed the possible consequences of tougher sanctions for companies and trading partners connected to Iran. 514

Japan’s Nikkei fell 0.74%, a smaller decline than the KOSPI’s, while China’s Shanghai Composite lost 0.59%. The contrast suggests that Monday’s market reaction was not a uniform repricing of geopolitical risk: sector exposure and expectations for technology earnings were also major drivers. 1718

Why India held up better—and what could change

India’s Sensex fell 0.22% and the Nifty 50 declined 0.14%, making the losses comparatively modest. 45 That resilience does not remove the country’s exposure to a prolonged energy shock.

If tensions eventually push crude prices materially higher, India could face a larger import bill, more pressure on inflation and greater demand for dollars from energy importers. Those forces could weigh on the rupee and on corporate margins. The key caveat is that this was a forward-looking risk on Monday: crude prices actually moved lower during the session.

West Texas Intermediate fell about 2.5% to $84.89 a barrel, while Brent crude also lost about 2.5% to $92.06. 8 Falling oil and lower Treasury yields provided some offset to the geopolitical and technology concerns, helping explain why the market response remained orderly rather than turning into a broad panic. 18

Australia was the outlier among the listed markets. The S&P/ASX 200 gained 0.66% to 9,163.30. 35 Its stronger performance came as other markets were absorbing technology-related selling and shifting expectations around energy and commodities, although one session is not enough to establish a lasting change in regional leadership.

What markets were watching next

The immediate focus shifted to a crowded macro and earnings calendar. Investors were preparing for Nvidia’s results, the Federal Reserve’s Jackson Hole gathering and a closely watched inflation report. These events could influence expectations for technology valuations, bond yields and the future path of U.S. interest rates. 1720

The practical takeaway is straightforward: the next move may depend less on the headline announcement itself than on whether sanctions are enforced more aggressively, whether tensions affect Gulf shipping or oil supply, and whether Nvidia’s results revive or weaken the semiconductor trade. On August 24, the market priced in uncertainty—but not a full-scale financial shock.