Indian stock markets experienced their worst weekly decline in three months, with both Sensex and Nifty indices falling significantly. This downturn is attributed to fresh concerns over potential US tariffs, particularly a bill targeting countries engaging with Russia's energy sector. Geopolitical uncertainty, including US actions related to Venezuela and Russian oil tankers, has heightened market volatility. Investors are also reacting to comments about a stalled US-India trade deal and are awaiting a US Supreme Court verdict on existing tariffs, leading to a broad-based sell-off and a significant drop in market capitalization.