The Indian stock market came under heavy selling pressure on Thursday, September 24, as rising crude oil prices and a sharp jump in US Treasury yields weighed on investor sentiment.

The Sensex and Nifty 50 fell by around 1% at the opening. The Sensex dropped roughly 556 points to 74,272, while the Nifty declined about 225 points, or nearly 1%, to around 23,222.

The sell-off came after Brent crude climbed above $102 a barrel and the US 10-year Treasury yield surged to 5.11%, its highest level since 2007.

Why did the Indian stock market fall?

There were several global factors behind Thursday's market decline rather than a single trigger.

The biggest concern was the sharp rise in crude oil prices. Brent crude had moved above the $102-per-barrel mark, raising concerns about inflation and India's import bill because the country relies heavily on imported crude oil.

Higher oil prices can put pressure on India's external balance and inflation outlook, while also increasing costs for industries that depend heavily on fuel and energy.

US bond yields add to market pressure

Another major trigger was the sharp rise in US Treasury yields.

The 10-year US Treasury yield jumped to 5.11%, with reports describing the level as the highest since 2007. The increase followed stronger economic data and weak demand at US government debt auctions.

Higher US bond yields can make fixed-income investments relatively more attractive and increase the discount rate used to value equities. This can put pressure on stock valuations, particularly in markets where valuations are relatively high.

Investors are also watching expectations surrounding US interest rates. Persistent inflationary pressure can reduce expectations of monetary easing and keep borrowing costs higher for longer.

Insurance and financial stocks under pressure

Financial stocks were among those facing significant selling pressure during the session.

HDFC Life, Bajaj Finance and other major financial names were among the stocks contributing to the decline.

Insurance stocks also came under pressure amid concerns surrounding proposed changes to insurance distribution regulations.

The Insurance Regulatory and Development Authority of India (IRDAI) has been examining changes related to the distribution of insurance products and expense-of-management rules. Investors are assessing how potential changes could affect insurers' costs, distributor payouts and profitability.

The uncertainty around the proposed regulatory changes added another layer of pressure to the sector.

What happened to midcap and smallcap stocks?

Despite the weakness in the major indices, the broader market has shown a different pattern.

Domestic institutional and retail flows have continued to provide support to midcap and smallcap stocks. However, analysts have also cautioned that elevated valuations could make these segments vulnerable if global pressures persist.

Geojit Investment's Chief Investment Strategist V.K. Vijayakumar said the sharp rise in crude oil and US bond yields were significant headwinds for the Indian market.

If crude oil remains elevated and global bond yields stay high, the pressure could eventually extend beyond large-cap stocks.

Foreign and domestic investor flows

Investor flows remain another important factor for the market.

According to NSE data reported ahead of Thursday's session, foreign institutional investors bought equities worth ₹1,617.45 crore on Wednesday, while domestic institutional investors bought stocks worth ₹2,341.46 crore.

Strong domestic buying can provide some cushion during periods of global volatility, although sustained increases in oil prices and bond yields remain important risks for the broader market.

What should investors watch next?

Market participants are likely to closely monitor three major factors in the coming sessions:

1. Crude oil prices — A sustained move above $100 could increase concerns about inflation and India's import bill.

2. US Treasury yields — Further increases could put additional pressure on global equity valuations.

3. Geopolitical developments — Any change in tensions surrounding the Middle East and US-Iran relations could have a direct impact on oil prices and market sentiment.

The Indian market had gained on Wednesday, with the Sensex rising 299.17 points and the Nifty advancing 117.80 points. Thursday's sell-off therefore came after two consecutive sessions of recovery.

Bottom line

Thursday's decline reflects a combination of global macroeconomic pressures rather than a single domestic trigger. Rising crude oil prices and higher US Treasury yields have increased uncertainty for equity investors, while regulatory concerns have added pressure to specific sectors.

The direction of crude prices, global bond yields and geopolitical developments will remain key factors for Indian equities in the near term.