Indian Markets Rebound as US Treasury Intervenes Amid Iran Tensions

Indian benchmark indices experienced significant volatility between August 19 and August 21, 2026, driven by geopolitical instability and fluctuating bond yields. The BSE Sensex and NSE Nifty initially fell on August 19, marking a seven-session decline for the Nifty. This downturn followed the expiration of a 60-day ceasefire between the Federal government of the United States and Iran, which sparked fears of energy supply disruptions and pushed Brent crude prices above $91 per barrel.

Market sentiment shifted on August 20 when the United States Department of the Treasury announced plans to more than double long-dated debt buybacks. This intervention lowered the 10-year Treasury yield to 4.65%, reviving risk appetite and attracting fresh foreign fund inflows. The Sensex jumped 628.04 points to settle at 77,537.72, while the Nifty rose to 24,231.85, snapping its losing streak.

However, gains remained fragile by August 21. The indices ended the week nearly flat as Brent crude climbed toward $94 per barrel. Investor caution returned following indications from US Treasury Secretary Scott Bessent that Washington could impose stringent sanctions on Iran. Analysts noted that while the Treasury's debt buybacks provided temporary relief, the combination of persistent inflation fears and Middle East instability continues to threaten corporate profitability and market momentum.