Aug 18: Nifty Declines for Sixth Consecutive Session as Brent Crude Surpasses $91 Amid US-Iran Tensions; Sensex Drops 492 Points

On August 18, 2026, the Indian stock market experienced continued pressure with the Nifty 50 index falling for the sixth straight trading day and the Sensex declining for the third consecutive session. These drops coincided with increased geopolitical tensions between the United States and Iran, which caused a sharp rise in Brent crude oil prices, exceeding the $91 per barrel threshold.

This spike in crude oil heightened concerns about global inflation and its potential impact on India’s economy.

Market Performance Overview

The Nifty 50 index closed below 24,200 after volatile trading ahead of the weekly derivatives expiry, while the Sensex ended the day down by 492.70 points (0.63%) at 77,235.46. The Nifty declined 132.75 points (0.55%), settling at 24,154.90.

Over the past six sessions, the Nifty has dropped 1.74%, reflecting worsening short-term market sentiment, while the Sensex has lost 1.08% over three sessions.

Sector Performance and Stock Movements

Selling pressure was most notable among large-cap technology stocks, with Infosys falling by 2.18%, Bharti Airtel by 1.78%, and HDFC Bank by 0.82%. In contrast, sectors such as pharmaceuticals, automobiles, and oil and gas performed relatively better.

The broader market showed mixed results; the BSE MidCap Index dipped 0.35%, whereas the SmallCap Index gained 0.19%. Market breadth remained negative with more declining shares than advances.

Impact of Global Factors

Brent crude for October 2026 delivery rose to $91.45 per barrel, up 0.20%, fueling concerns over a prolonged geopolitical conflict affecting India’s import costs and inflation. A weaker Indian rupee, trading around 95.65 against the US dollar compared to the previous close of 95.42, amplified inflationary worries as oil imports are dollar-denominated.

Additionally, the yield on India’s 10-year government bonds increased slightly to 6.824% from 6.804%.

Global markets reflected similar caution: European stocks fell to roughly two-week lows, and Asian markets ended mixed due to uncertainty over US-Iran ceasefire talks.

US stock markets also declined, with the Dow Jones down 0.51%, the S&P 500 down 0.52%, and the Nasdaq retreating 0.32%. Investors awaited the July Federal Reserve meeting minutes for clues on future interest rate moves, especially since three policymakers had dissented previously in favor of a rate hike.

Economic Update from China

China reported slower economic activity in July, including a 0.6% year-over-year increase in retail sales, a 6.7% drop in urban fixed-asset investments over seven months, and industrial output growth slowing to 4.5% from 5.3%. These figures raised concerns about global growth prospects.

Corporate Highlights

On a positive note, Milky Mist Dairy Food debuted strongly on the Bombay Stock Exchange, closing with a nearly 30% premium over its issue price. Sigma Advanced Systems also rallied 5% after securing government orders worth approximately Rs 155 crore for anti-drone vehicles.

Shares of Paytm’s parent company, One 97 Communications, declined following a large block stake sale proposal associated with its founder. Nelco shares fell sharply by 12.62% after announcing a $20 million investment in a US-based pre-revenue satellite communications company, raising investor concerns over commitment to an early-stage venture.

Other companies such as DCX Systems, Netweb Technologies India, KPI Green Energy, and Highway Infrastructure reported positive developments including purchase orders, institutional placements, and project commissions. Meanwhile, Goldiam International and Ceigall India faced declines despite securing new contracts.

Primary Market Activity

In the primary market, subscription levels varied: Sunshine Pictures received a strong oversubscription, while Shankesh Jewellers and Horizon Industrial Parks remained under-subscribed. Lalithaa Jewellery Mart continued to attract robust investor interest.

Outlook and Market Sentiment

Looking ahead, market sentiment is expected to hinge on developments regarding US-Iran relations, global crude oil prices, foreign investment flows, and international bond yields.

The combination of elevated oil prices, rupee depreciation, and high US Treasury yields poses challenges for Indian equities. However, domestic investor participation and select sector performances may provide some support.

Participants will closely observe upcoming derivative expiries, central bank communications, and geopolitical shifts to assess whether the market stabilizes or faces continued corrections.

Key Takeaways

  • Nifty 50 declined for sixth consecutive session; Sensex fell for the third straight day amid escalating US-Iran tensions.
  • Brent crude surpassed $91 per barrel, intensifying inflation concerns and impacting Indian import costs.
  • Large-cap technology stocks faced significant selling pressure, while pharmaceuticals, automobiles, and oil & gas sectors held up better.
  • Currency depreciation and rising bond yields add to economic challenges amid volatile global markets.
  • Market outlook remains cautious with key focus on geopolitical developments, central bank policies, and upcoming derivative expiries.