CSD Shorts Surge 45% in a Week — Even as the ETF Rallies Hard

CSD, the Invesco S&P Spin-Off ETF, has produced one of the more striking divergences in the ETF space this week: short sellers are piling in at a pace not seen in months, yet the fund itself is up sharply.

Short interest in CSD has risen almost 70% over the past month. The weekly jump alone is 45%, with estimated short shares climbing to around 43,100 — equivalent to 5.3% of free float. That level is meaningful for an ETF. And it has moved almost entirely in the past four weeks, from roughly 22,000 shares in late March to where it is today. Whatever the thesis behind this positioning, it is new and it is building fast.

The borrow market reflects some of that pressure, though availability remains workable. Cost to borrow has been volatile, ranging between roughly 5.3% and 11.3% over the past six weeks, and currently prices around 7.3% — down from a late-March peak above 10% but still elevated by ETF standards. Availability has tightened considerably through April, with borrowing demand easily absorbing available supply on multiple sessions. The lending pool is not exhausted — this is not a squeeze setup in the classic sense — but the borrow cost signals there is genuine competition for shares.

Against this, the ETF itself is up 5.1% on the week and 16.1% over the past month, closing at $132.48. That is the precise tension in this note: short interest is almost doubling in a month that has also been a strong one for the underlying spinoff names. Options positioning offers a hint at the market's directional lean. The put/call ratio is running at just 0.16 — well below its 20-day average of 0.23 and near the low end of the past year's range (the 52-week low reads 0.00). Calls are heavily outnumbering puts. That is a bullish sentiment signal, and it cuts directly against the short-building story in the lending market.

The ORTEX short score has climbed from around 53 in late April to 59.4 this week — still below 60, and therefore not in extreme territory, but the trend is clearly upward and the recent acceleration mirrors the jump in shares short. The combined score of 59.1 tells the same story: elevated and rising, but not yet at a level that would typically precede a squeeze.

One structural note worth keeping in mind: CSD tracks spinoffs, which are inherently idiosyncratic holdings. Short interest in a spinoff ETF can rise when investors use the fund as a hedge against a specific holding inside it, or when arbitrageurs take paired positions across the spinoff and parent. The 45% weekly jump in short shares is large enough to suggest something targeted is happening, rather than a pure directional bet against the basket.

The number to watch is whether short interest continues to build through next week. If it does while the ETF price holds or rises further, the squeeze risk — remote today given availability — becomes a more live conversation.