Investors have been repositioning sharply across European airline stocks since the outbreak of Middle East hostilities, with Ryanair Holdings PLC (LSE:RYA) emerging as the clear defensive favourite while short positions have built against carriers more vulnerable to elevated fuel prices.

This is Citi's analysis of positioning data from institutional investors, with the analysis showing that sector positioning has turned more negative over both the past week and month.

Investors have increased short exposure in Wizz Air Holdings PLC (AIM:WIZZ), easyJet PLC (LSE:EZJ) and Air France-KLM, which Citi characterises as the most operationally and financially leveraged carriers and therefore most exposed to sustained fuel price pressure.

British Airways owner International Consolidated Airlines Group SA (LSE:IAG) has also seen a shift, with long positioning that had been particularly heavy now moving to a more balanced level as investors take profits or hedge against further volatility.

Ryanair has bucked the trend, with long positioning increasing over the past week as investors gravitate toward what Citi describes as the carrier best equipped to weather near-term geopolitical turmoil. This view, the bank said, is "widely and rightly held".

The Irish carrier's low-cost model, strong hedging position and predominantly intra-European network make it less exposed than peers to Middle Eastern route disruptions and transatlantic demand softness.

Lufthansa is a notable outlier in the data. While positioning has turned more negative over the past month, that shift predates the onset of the conflict, despite the German carrier having particularly high exposure to crack spreads, the margin between crude oil and refined jet fuel prices that has widened sharply since hostilities began.

Citi said near-term share prices across the sector would remain heavily dictated by fuel price movements.