Mumbai, April 9 -- Equity benchmark indices Sensex and Nifty surged nearly 4% on Wednesday, following an impressive rally in global markets and a drop in crude oil prices after the US and Iran announced a two-week ceasefire. The RBI decision to keep the policy repo rate unchanged, heavy buying across all sectors and a strengthening rupee against the US dollar also improved investor sentiment, traders said.Rallying for the fifth day in a row, the 30-share BSE Sensex jumped 2,946.32 points or 3.95% to settle at 77,562.90, registering its best trading day in five years. During the session, it surged 3,018.96 points or 4% to 77,635.54. A total of 3,859 stocks advanced, while 537 declined and 101 remained unchanged on the BSE. The 50-share NSE Nifty soared 873.70 points or 3.78% to end at 23,997.35, the highest single-day rally in 11 months. It rallied 901.5 points or 3.89% to 24,025.15 during intra-day trade. "The rally was primarily driven by a sharp improvement in global sentiment following the announcement of a temporary ceasefire between the US and Iran, which led to a significant cooling in crude oil prices and eased concerns around inflation and global growth," Ajit Mishra, SVP, Research, Religare Broking Ltd, said. Additionally, the Reserve Bank of India's policy decision to maintain the status quo on rates with a neutral stance was perceived as supportive for equities, he pointed out. From the Sensex pack, InterGlobe Aviation jumped the most by 8.22%. Larsen & Toubro, Bajaj Finance, Mahindra & Mahindra, Axis Bank and Maruti were also among the prominent gainers. In contrast, Tech Mahindra, Sun Pharma and Power Grid were the laggards. All sectoral indices ended higher. Realty index jumped 6.76%, auto (6.55%), BSE PSU Bank (5.79%), Bankex (5.72%), Private Banks index (5.62%), Financial Services (5.48%), Services (5.22%), Consumer Discretionary (5.11%) and Industrials (4.87%). On the other hand, the BSE MidCap Select index jumped 4.93%, and the SmallCap Select index rallied 4.01%. Brent crude, the global oil benchmark, tumbled 13.89% to $94.09 per barrel. The rupee appreciated 47 paise to close at 92.59 (provisional) against the US dollar on Wednesday. In Asian markets, South Korea's benchmark Kospi surged 6.87% and Japan's Nikkei 225 index jumped 5.39%. Shanghai's SSE Composite index and Hong Kong's Hang Seng index also recorded sharp rallies. European markets were trading significantly higher. US markets ended flat on Tuesday. "The ceasefire announcement sharply reduced fear and risk-off sentiment, with India's volatility index dropping over 20%, indicating a swift compression in uncertainty. This positive sentiment was mirrored across global markets, as the US, European, and Asian indices posted a broad-based recovery, reinforcing the strength of the current rally," Ponmudi R, CEO of Enrich Money, an online trading and wealth tech firm, said. Energy markets reacted sharply to the ceasefire developments, he said. "With Iran signalling the possibility of safe passage through the Strait of Hormuz during this two-week window, Brent crude corrected sharply towards the $92 mark," Ponmudi added....