TAN shorts keep building even as the ETF bounces

The Invesco Solar ETF TAN is running two contradictory signals at once: short interest has continued to climb to its highest level in months, yet the ETF posted a 3% gain on the week to close at $43.34, and options traders are now tilting more toward calls than they have in some time.

The short rebuild flagged in the previous note has not stopped. Short interest has pushed further to 10.6% of the free float, up another 9.7% on the week and now 40% above where it was a month ago. In share terms, shorts have grown from roughly 1.33 million in early October to nearly 2.1 million by November 3. That is a sustained, deliberate accumulation, not a single-session spike. The ORTEX short score has held in the high 50s to low 60s throughout, confirming the bearish positioning remains active. What has changed from the October 28 note is the size: the short book has expanded meaningfully even as the ETF has moved against it this week.

The borrow market is not adding pressure on shorts yet. Availability has actually loosened compared to mid-October levels, with roughly 198% availability now (around 6.4 million shares still available to lend against the 2.1 million already borrowed). That is well above the 52-week low of 6.2%, meaning the lending pool is comfortable and there is no mechanical squeeze risk on the horizon. Cost to borrow has drifted slightly lower on the week to 4.9%, though it is around 33% above where it was a month ago. The borrow cost trend confirms demand for shorts has been rising, but not to a level that makes the trade expensive enough to force covering.

Options positioning has flipped sharply in the other direction. The put/call ratio dropped to 0.54, well below its 20-day average of 0.68 and sitting roughly 1.2 standard deviations below that mean, making it one of the more call-heavy readings of the past year. Through September and early October, the PCR was consistently above 0.8, often near 0.9. The rotation toward calls since late October is striking in its speed, and it runs directly counter to the short interest trajectory. Two distinct camps are forming: shorts adding to a conviction bet against solar, while options buyers are paying for upside exposure.

The tension between these two signals is the story heading into November. TAN carries no upcoming earnings event of its own, so the next catalyst will come from within the portfolio, specifically from names like Enphase and SunRun as Q3 results continue to filter through, and from any policy signals around the renewable energy sector. With shorts at multi-month highs, availability still comfortable, and call buyers rotating in aggressively, the week's price action and what drives it next will be worth watching closely.