The Nifty Auto index jumped 2.2% as GST cuts boosted sentiment. Tax on small cars, hybrids, motorcycles (under 350cc), and tractors was reduced, while three-wheelers moved to 12%. M&M surged 6.7% on tractor relief; Eicher rose 2.7% as Royal Enfield bikes fall under 350cc. Hero, Bajaj, TVS, Tata Motors, and Maruti also gained. Premium vehicles face a 40% GST.