Jet fuel prices have risen for three consecutive months, prompting IndiGo to increase fares and introduce a fresh fuel surcharge. From October 6, the airline will add ₹100 to ₹350 on domestic flights, depending on distance, reflecting the latest rise in domestic jet fuel (ATF) from ₹121 to ₹137 a litre – a 13.2% jump and the third monthly increase in a row. Fuel constitutes about 40% of an airline’s operating costs, so the hike is felt quickly across the industry, creating a brief lull in profitability for the carrier.

IndiGo’s June‑quarter results show that fuel expense surged 85.7% to ₹10,833 crore from ₹5,833 crore a year earlier, driven by a roughly 50% rise in Brent crude and a 120% rise in Singapore jet fuel prices. The rupee’s depreciation, weakening from about ₹85 to ₹95 per dollar between June 2025 and June 2026, further amplified the cost shock, as the airline pays for fuel, aircraft leases and maintenance largely in dollars. The company’s strong balance sheet, with free cash of ₹39,039 crore at the end of June, helps absorb the shock.

The airline raised passenger yield by 21.3% in the June quarter, yet revenue and cost measured on the same unit – available seat‑kilometre – revealed a reversal of its previous advantage. A year ago, IndiGo earned 55 paise more per seat‑km than it spent; in the June quarter it spent about 5 paise more than it earned. Of every rupee of extra cost per seat‑km, fares and ancillaries recovered roughly 57 paise, indicating a pass‑through ratio of about 57%.

Despite holding a 65%+ market share, IndiGo lost share in a shrinking market. Domestic airlines carried 1.21 crore passengers in August, 6.34% fewer than a year earlier, and IndiGo also lost share within that market. The August DGCA data, published on September 23, raise questions about the airline’s pricing power, suggesting that the industry is under overall stress and that competitors may not immediately follow price hikes. The source cites Loktej and Business Standard articles for these figures.

The stock has remained relatively calm amid these challenges. On October 7, IndiGo traded at ₹4,988, down about 5% versus an almost 14% year‑to‑date fall in the Nifty50. The company’s guidance for flat capacity and a 25% rise in passenger revenue per seat‑km, combined with its strong balance sheet, has helped temper market reaction. Investors are watching whether the airline can shift from price‑led to volume‑led growth once fuel and the rupee settle.

Investors can monitor two key metrics: the pass‑through ratio and market share. A ratio above 100% indicates fares rising faster than costs, while a ratio below 100% shows the airline absorbing part of the shock. If the ratio climbs while IndiGo’s share remains near 65% or higher, pricing power is real; if it climbs only as share and traffic fall, the margin is being bought with passengers. The upcoming ATF price revisions on the 1st of each month provide an early read on the next quarter’s fuel bill before the airline reports it, and festive travel demand may help the carrier overcome this brief lull.