Why These Stocks Are Rising and Falling Today: Tata Chemicals, Firstsource Solutions & Afcons Gain; Solar Industries, Welspun Corp & Netweb Technologies Decline

Indian benchmark indices remained under pressure around noon on September 15, 2026, with both the Sensex and Nifty 50 trading in the red. The Sensex was down 113.24 points, or 0.15%, at 74,668.52, while the Nifty 50 declined 60.55 points, or 0.26%, to 23,337.55.

The market opened higher, but the early gains failed to hold as concerns over rising crude oil prices continued to weigh on sentiment.

Amid the broader weakness, IT stocks stood out as a bright spot, with all five top Nifty 50 gainers coming from the sector. However, elevated crude prices remained a key concern for investors. Brent crude was trading near $107 a barrel amid rising tensions in the Middle East.

The rupee also remained under pressure after declining 33 paise in the previous session to close at 94.82 against the US dollar.

Top Gainers for September 15: Tata Chemicals, Firstsource Solutions and Afcons Gain Up to 20%

Tata Chemicals Ltd Hits 20% Upper Circuit

Tata Chemicals Ltd emerged as the top gainer in the Nifty 500 index on September 15, 2026. Tata Chemicals Ltd share price was trading at ₹734.90 at 11:59 am, reflecting a gain of 19.99%.

The rally came after the Reserve Bank of India (RBI) rejected Tata Sons' request to surrender its Core Investment Company (CIC) registration. This has brought the mandatory public listing of the Tata Group holding company back into focus.

Tata Chemicals Ltd holds a roughly 2.53% stake in Tata Sons.

Firstsource Solutions Ltd Rises 16%

Firstsource Solutions Ltd also emerged as one of the top gainers in the Nifty 500 index. Firstsource Solutions Ltd share price was trading at ₹288.10 at 11:35 am, reflecting a gain of 16.36% from the previous close.

Volumes stood strong at 173.7 lakh, compared with its 30-day average of 27.5 lakh.

Afcons Infrastructure Ltd Rises 9%

Afcons Infrastructure Ltd share price was trading at ₹278.55 at 11:59 am, reflecting a gain of 9.75%.

The rally was linked to the same Tata Sons listing catalyst. While Afcons Infrastructure Ltd is not a Tata Group company, it is the flagship infrastructure and engineering arm of the Shapoorji Pallonji Group.

The Shapoorji Pallonji Group holds a roughly 18.4% stake in Tata Sons.

The RBI's rejection of Tata Sons' request to surrender its Core Investment Company registration has brought the mandatory public listing of Tata Sons back into focus under the applicable Upper Layer NBFC regulations.

Top Losers for September 15: Solar Industries, Welspun Corp and Netweb Technologies Fall Up to 12%

Solar Industries Falls Over 11%

Solar Industries India Ltd emerged as the top loser in the Nifty 500 index on September 15, 2026. Solar Industries India Ltd share price was trading at ₹19,700 at 11:59 am, reflecting a decline of 11.62%.

The fall came after the company announced a proposed ₹12,951 crore acquisition of South Africa-based Omnia Holdings. The stock reversed its recent gains after hitting a 52-week high.

Welspun Corp Falls Over 6%

Welspun Corp Ltd also emerged as one of the top losers in the Nifty 500 index. Welspun Corp Ltd share price was trading at ₹2,491 at 11:59 am, reflecting a decline of 6.93% from the previous close.

The fall was largely attributed to profit booking after the stock's strong rally in recent weeks.

Netweb Drops Over 5%

Netweb Technologies India Ltd shares fell more than 5% in morning trade on September 15, 2026. Netweb Technologies India Ltd share price was trading at ₹4,741.50 at 11:59 am, reflecting a decline of 5.68% from the previous close.

The fall was largely attributed to profit booking.