CART: Short Sellers Build as Call Buyers Double Down

Why this matters: Two days after our last note, the divergence on CART has deepened. Short interest has climbed further, the cost to borrow has jumped, and options traders are still piling into calls. The three signals are now moving simultaneously — and in opposite directions.

Short Interest Keeps Rising

SI hit 6.7% of free float as of September 24. That is up 11.8% over the past week and nearly 19% over the past month. The pace has accelerated. In early September, short shares sat around 14.5 million. They peaked at 18 million on September 23 before settling at 17.6 million. That is a meaningful build in a short period.

The cost to borrow has risen with it. It reached 0.40% on September 24 — up 76% week-on-week. That is still a low absolute rate. But the direction matters. A near-doubling in a single week suggests incremental demand for borrows, not just routine pricing noise.

Despite this, the borrow market is not tight. Availability stands at 871% of current short interest. That is down sharply from over 2,800% two weeks ago — a rapid tightening — but 103 million shares remain available to borrow. Short sellers are not squeezed.

Call Buyers Aren't Flinching

The put/call ratio sits at 0.34 — near the 2-year low of 0.23. It has held below 0.36 for four straight sessions. The 20-day average is 0.42. At -1.68 standard deviations below that mean, call demand is statistically extreme.

The stock closed at $43.26 on September 24. It is down 16.4% over the past month. Options traders are not rotating to puts. They are adding to calls into the weakness.

November 6 is the next earnings date. CART jumped 10.6% after its last report. That likely explains some of the call positioning — traders may be buying cheap premium ahead of a known catalyst.

Analysts Still Constructive

The mean analyst price target is $58.14 — a 34% premium to current prices. Argus raised its target to $58 on September 2. Barclays is at $77. Most targets were set or raised post-earnings in early August when the stock was trading above $48. The stock has since given up those gains, widening the gap between where the stock trades and where analysts think it should.

That gap is now substantial. It gives context to why call buyers are active: if analysts are right, the stock is deeply discounted.

Data Summary

• SI % of Free Float: 6.7%, up 11.8% week-on-week and 19% month-on-month
• Cost to Borrow: 0.40%, up 76% over one week
• Borrow Availability: 871% of short interest — ample supply despite recent tightening (was 2,800%+ two weeks ago)
• Put/Call Ratio: 0.34, near 2-year low; z-score -1.68 vs 20-day mean
• Stock Price: $43.26, down 16.4% over one month
• Mean Analyst Target: $58.14 (34% above current price)
• Next Earnings: November 6, 2026

What to watch: Whether the availability drop continues. A move below 300% would signal a genuinely tightening borrow market and could change the short-selling economics materially.