Citi data shows positioning turned universally negative last week, with IAG and Ryanair suffering the sharpest falls.
Investor sentiment across European airlines deteriorated sharply last week, with positioning moving unanimously negative amid mounting concern over fuel supply, according to Citi.
The US bank's quantitative team tracked long and short positioning across the sector, finding that consensus longs have been entirely eliminated.
International Consolidated Airlines Group SA (LSE:IAG) and Ryanair Holdings PLC (LSE:RYA), historically the two most favoured names in the sector, recorded the steepest negative moves week on week.
Citi noted the market appeared slow to react to bearish comments made by Ryanair's chief executive the previous week, in which he flagged softer summer fares.
Overall, easyJet carries the most negative positioning in the sector, though it recorded one of the smaller week-on-week shifts.
Lufthansa and Wizz Air sit close behind easyJet in terms of negative sentiment, with both also registering among the more modest week-on-week moves.
Air France-KLM's positioning remains broadly in line with the wider sector, running slightly negative, with a similarly contained weekly shift.
Citi's data suggests the sell-off has been broad-based rather than concentrated in individual names, with fuel supply anxiety driving investors away from the sector as a whole.