Why These Stocks Are Rising and Falling Today: Syrma SGS Technology, Adani Total Gas & Jyoti CNC Automation Gain; Tata Chemicals, New India Assurance & Tata Investment Corporation Decline

Indian benchmark indices continued to hold gains in afternoon trade on September 18, 2026. The Nifty 50 rose 0.20% to 23,318.05, while the BSE Sensex added 0.20% to 74,466.52 as of 12:25 pm. Tata Group stocks remained under pressure, while most sectoral indices traded firm.

Top Gainers for September 18: Syrma SGS Technology, Adani Total Gas and Jyoti CNC Automation Gain Up to 8%

Syrma SGS Hits All-Time High

Syrma SGS Technology Ltd emerged as the top gainer in the Nifty 500 index on September 18, 2026. At 11:52 am, the Syrma SGS Technology share price was trading at ₹1,739.50, up 7.53% from its previous close on the NSE. At this level, the stock was trading at its all-time high.

Trading volumes remained strong at 68.60 lakh shares, compared with the 30-day average volume of 19.70 lakh shares.
Recently, the company’s Managing Director, Jasbir Singh Gujral, said its newly commissioned joint venture with Italy-based Elemaster has the potential to become a sizeable business. He estimated that the joint venture could generate revenue of $50 million to $100 million over the next three to five years.

Adani Total Gas Surges Over 6%

Adani Total Gas Ltd was also among the top gainers in the Nifty 500 index. At 11:52 am, the Adani Total Gas share price was trading at ₹628, up 6.98% from its previous close on the NSE.

Trading volumes stood at 58.80 lakh shares, compared with the 30-day average volume of 10.10 lakh shares.

Jyoti CNC Automation Rises 6%

At 11:52 am, the Jyoti CNC Automation share price was trading at ₹1,040.95, up 6.13% from its previous close on the NSE.
Trading volumes stood at 12 lakh shares, compared with the 30-day average volume of 14.20 lakh shares.

Top Losers for September 18: Tata Chemicals, New India Assurance and Tata Investment Corporation Fall Up to 8%

Tata Chemicals Falls Over 8%

Tata Chemicals Ltd emerged as the top loser in the Nifty 500 index on September 18, 2026. At 11:52 am, the Tata Chemicals share price was trading at ₹714, down 8.38% from its previous close.

The decline was driven by selling pressure across Tata Group stocks amid the ongoing corporate governance dispute between Tata Trusts and the Tata Sons board.

Regulatory developments involving the Reserve Bank of India (RBI) also weighed on investor sentiment. Tata Chemicals holds approximately 2.53% in Tata Sons, which has contributed to the stock’s decline amid the developments.

New India Assurance Drops Over 4%

At 11:52 am, the New India Assurance Company Ltd share price was trading at ₹187.90, down 4.64% from its previous close.
The decline came amid profit booking following the opening of the NSE IPO.

New India Assurance Company Ltd holds a 1.42% direct stake in the National Stock Exchange of India (NSE), according to the exchange’s Red Herring Prospectus. The company could therefore benefit from any value unlocking following the listing.

Tata Investment Corporation Falls Over 3%

At 11:52 am, the Tata Investment Corporation Ltd share price was trading at ₹696.05, down 3.23% from its previous close on September 18, 2026.

The decline came amid developments surrounding Tata Sons, in which Tata Investment Corporation holds a 0.08% stake.
Tata Trusts has described the Tata Sons board’s decision to reappoint N. Chandrasekaran as Chairman as “illegal”. Tata Trusts has also publicly opposed the proposed IPO of Tata Sons, favouring private structural changes to meet RBI regulations.