Shares of Tata Consultancy Services (TCS) recorded their worst single-day decline since the COVID-19 market crash of 2020, plunging more than 8% on Wednesday. The IT bellwether led losses across the technology pack and emerged as one of the biggest drags on the benchmark Sensex and Nifty indices.TCS shares tumbled sharply to close at Rs 2,241.70 apiece on NSE. Today marked the sharpest single-day fall in the IT stock since a 9% crash on March 12, 2020, when markets saw a historic plunge as the World Health Organisation declared COVID-19 a pandemic.Today’s sharp decline in IT stocks comes after a sharp rally. The Nifty IT index had surged more than 4% on Tuesday, marking its biggest single-day gain since May 2026. The index rallied nearly 8% over the previous three sessions, even as the Nifty 50 fell 2% during the same period. TCS shares had climbed 8% across the two sessions to Tuesday's close of Rs 2,446.90. However, Wednesday's sharp sell-off wiped out the stock's entire gain from the recent rally.Technical view on TCSTCS witnessed a sharp decline today, erasing the gains from the previous session. The stock faced strong resistance near its 100-day EMA zone of Rs 2,600–2,605, triggering a sharp reversal, said Sudeep Shah, Head of Technical Research and Derivatives Research at SBI Securities.“Momentum indicators have also weakened, with the RSI turning lower after approaching the 60 mark, signalling a loss of bullish momentum. Additionally, the stock has slipped below the Bollinger Band midline, a level often considered an important support. With today's fall, TCS has moved below key short and long-term moving averages, indicating a deteriorating trend,” Shah explained, adding that the Rs 2,210-2,200 zone remains a crucial support, and a breakdown below this level could accelerate further downside.Harshal Dasani, Business Head at INVasset PMS, meanwhile, said that TCS’s chart has moved from weakness to a breakdown test. “The 9% fall after a 6.53% rebound in the previous session confirms that the earlier move was a dead cat bounce, not fresh accumulation. When a large-cap stock gives back a relief rally this quickly, the market is not reacting to one bad headline. It is repricing the entire low-growth IT model,” he noted.The key level that investors should watch out for now is the 52-week low near Rs 2,206, according to Dasani. Also read: AI, data centre boom powers these 9 stocks up to 477% in 2026. Can you still join the party?He added that a decisive close below that zone would weaken the structure further because the stock has not built a meaningful base beneath it. On the upside, Rs 2,400 to Rs 2,450 becomes the first heavy supply zone, because that is where the recent bounce failed. “Until TCS reclaims that band with strong participation, rallies are likely to meet selling pressure. The company remains a high-quality franchise, but the chart is saying quality alone is not enough when growth is weak, AI risk is rising, and valuations still leave little margin for error,” he said.(Disclaimer: Recommendations, suggestions, views and opinions given by the experts are their own. These do not represent the views of The Economic Times)