Stock market down today: 5 reasons behind May 18 fall

Market snapshot: Sensex and Nifty slide over 1%

Indian equity benchmarks opened weak and extended losses on Monday, May 18, 2026, as risk sentiment deteriorated across global markets. The BSE Sensex fell more than 1,000 points in early trade and slipped below the 74,300 mark. The NSE Nifty 50 dropped more than 300 points and traded under 23,350. At 10:05 am, the Sensex was at 74,334.75, down 903.24 points or 1.20%, while the Nifty was at 23,360, down 283.20 points or 1.20%. Broader markets also weakened, with the Nifty Midcap 100 and Nifty Smallcap 100 falling more than 1% each.

What triggered the selloff on Dalal Street

The fall was driven by a cluster of macro and geopolitical factors that tightened risk appetite. Elevated crude oil prices added to inflation and current account concerns for India, which imports most of its oil needs. The rupee hit fresh record lows against the US dollar, increasing the cost of dollar-denominated imports and weighing on foreign investor returns. Global bond yields rose sharply, making fixed-income assets relatively more attractive than equities, especially for overseas investors. Meanwhile, fresh remarks from US President Donald Trump on Iran increased uncertainty around the Middle East conflict and its impact on energy supplies.

Reason 1: Crude oil climbs above $110, adding macro pressure

Oil prices rose again as geopolitical tensions pushed markets to price in supply risks. Brent crude advanced nearly 2% to trade around $111 per barrel, while WTI crude gained more than 2% to move above $108 per barrel during Monday morning trade. Another update showed Brent crude up 1.72% at $111.14 per barrel and WTI up 2.02% at $107.55 per barrel. Brent crude for July delivery rose 1.84% to hit $111.29 a barrel. The article also flagged fears around disruption through the Strait of Hormuz, a key global oil shipping route.

For India, higher crude is a direct headwind because the country imports nearly 85% of its oil requirements, with some estimates in the report placing it around 90%. Higher oil prices can worsen imported inflation risks, pressure corporate margins through higher input costs, and strain the current account deficit. The report also noted that petrol and diesel prices in India were increased by Rs 3 per litre for the first time in nearly four years, adding to the inflation narrative in a higher crude environment.

Reason 2: Rupee hits a fresh record low against the dollar

The rupee fell to an all-time low of 96.18 against the US dollar on Monday, surpassing its previous lifetime low of 96.1350. Another data point in the report put the record low at 96.20, while a separate update cited 96.2275 after a nearly 0.3% fall. This marked the fifth straight trading session in which the rupee touched a fresh record low. The article said the rupee has declined 5.5% since the Iran-US conflict began on February 28, and described it as the weakest performer in Asia so far in 2026.

A weaker currency matters for equities because it can worsen inflation dynamics by making imports costlier, and it can reduce the attractiveness of Indian assets for foreign investors once currency impact is included. Jateen Trivedi, VP Research Analyst for Commodity and Currency at LKP Securities, said market participants remain cautious amid fears that elevated crude prices may persist, and cited a near-term rupee range of 95.55 to 96.25. Vijayakumar, Chief Investment Strategist at Geojit Investments, warned that further rupee depreciation could aggravate the cycle of rupee weakness and FPI selling, and said measures to strengthen the rupee are due and likely soon.

Reason 3: Bond yields jump as investors reassess inflation and risk

Bond yields across major economies surged to unprecedented levels after a selloff in global debt markets pushed bond prices down and yields up. The report highlighted Japan as another market seeing a steep rise in bond yields. Rising yields typically tighten financial conditions, especially for risk assets, and can pressure equity valuations.

In the US, the 10-year Treasury yield rose as well, with the report citing moves to around 4.626 and 4.62%. The article linked the higher US 10-year yield to weaker appetite for emerging market risk, given the inverse relationship often seen between higher US yields and flows into riskier assets.

Reason 4: Trump warning to Iran lifts geopolitical risk premium

Geopolitical concerns intensified after US President Donald Trump posted a fresh warning to Iran, urging it to “get moving, FAST,” while stating “TIME IS OF THE ESSENCE.” The report said negotiations covering uranium stockpiles, sanctions relief, and compensation linked to conflict remained deadlocked. Another mention, citing an Axios report, said Trump warned the “clock is ticking” as he sought a better proposal from Iran.

The report also pointed to rising instability in the Middle East, including a drone strike that triggered a fire at a nuclear power plant in the UAE and Saudi Arabia intercepting three drones. These developments added to the risk premium in energy markets and contributed to a broader risk-off move across equities.

Reason 5: Global and Asian equities sell off, spilling into India

Weak global cues amplified the domestic selloff. The report said global markets witnessed a sharp selloff as renewed geopolitical worries triggered a broad-based decline in equities. Asian equities fell amid concerns around the Strait of Hormuz, with markets across China, Hong Kong and Japan down 1% to 1.4% in one update. Indonesia’s Jakarta Stock Exchange Composite was cited as plunging 4.5%, highlighting the severity of risk aversion.

As global equities fall, correlations typically rise during risk-off phases, and Indian markets often see additional pressure through foreign flows and currency impact. The report also referenced GIFT Nifty trading lower pre-open, indicating a negative start for the Nifty50 as oil prices rose on renewed tension.

FPI outflows add to pressure on sentiment

Foreign portfolio investor selling remained a key overhang in the narrative. The article cited data compiled from NSDL showing foreign outflows in May at Rs 27,048 crore, taking 2026 outflows to Rs 2,19,017 crore so far. It also noted that prolonged pressure on the current account deficit and sustained FPI selling were beginning to weigh on domestic markets.

The market impact is visible when currency weakness and global yields rise together, since both can reduce relative returns for overseas investors. In such conditions, even strong domestic narratives tend to take a back seat to risk management, particularly in large-cap financials and index heavyweights.

Key numbers at a glance

What investors are watching next

Near-term market direction is likely to remain linked to crude prices, the rupee’s stability, and updates from the Middle East. The report flagged the Strait of Hormuz as a key variable, with broker commentary suggesting elevated Brent levels could persist in a $105 to $110 range if disruption risks stay high. Investors will also track whether measures are introduced to stabilise the currency, given repeated record lows.

For equity markets, the combination of high oil, rising global yields, and currency weakness typically tightens conditions for risk assets. Any cooling in these variables, or clarity on geopolitical developments, could influence intraday volatility and foreign flow behaviour, which the report identified as a central pressure point.

Conclusion

Indian markets fell sharply on May 18, 2026 as crude climbed above $110, the rupee hit record lows, US bond yields rose, and Middle East tensions escalated after Trump’s warning to Iran. With broader Asian markets also under pressure and foreign outflows remaining significant, investors are likely to stay focused on oil, yields, currency moves, and geopolitical updates in the days ahead.