Air Canada shorts double in a week with earnings tomorrow

Air Canada reports Q3 results tomorrow evening, and the most striking thing about this week's setup is not the price action but the short interest. Shares borrowed against the stock have roughly doubled over the past month, a move the data puts at 3.7 standard deviations above the airline's typical weekly shift.

Short interest climbed 64% in one week to 3.5% of the free float, now sitting at around 10.3 million shares. A month ago it was closer to 4 million. That is a rapid build, yet the borrow market tells a different story: availability is at 556%, meaning for every share already lent out there are more than five still available. Cost to borrow has fallen 91% over the past month to just 1.35%, having spiked to over 15% briefly in late September. The lending pool is loose. Whoever built the short position this month paid almost nothing to do it, and there is plenty of room for others to follow.

The analyst community is constructive. The consensus mean price target is CAD 32.69 against a closing price of CAD 22.14, implying roughly 48% upside on the Street's view. The analyst recommendation factor ranks in the 100th percentile of its universe, the strongest possible reading. EV/EBITDA has drifted up over the past month to 3.7x, while price-to-book has compressed 17% over 30 days to 1.3x, reflecting the 19% drawdown the stock posted over the past month. Earnings yield and EV/EBIT factor scores are middling, ranking in the 54th and 23rd percentiles respectively, which points to value that is not yet compelling on a profitability basis.

The stock has recovered 2.6% this week to CAD 22.14, but that trails the median of its closest peers. JBLU jumped 19% on the day, UAL gained 7% on the week, DAL added 6.3%, and AAL rose 4.1%. Air Canada's weekly move of 2.6% sits at the low end of that group, a meaningful underperformance heading into its own print. The month-long 19% decline is the sharper contrast: most of those peers held up better over October.

The earnings history adds useful texture. The last three Air Canada results produced large moves: a 19% jump the day after the August 2026 print, an 11.5% gain in August, and a 2.4% decline in Q1. The five-day moves were also wide, from 7% to 16%. The stock has rewarded and punished holders sharply around results, which makes the timing of the short rebuild notable.

Tomorrow's print is the specific event to watch. The short interest surge happened almost entirely in the week before results, which raises the question of whether it reflects a genuine fundamental view or positioning ahead of a volatile event. The borrow cost and availability data suggest the former has been cheap and easy.