CSM: Noise in the Borrow Market, Calm Beneath the Surface

CSM, the ProShares Large Cap Core Plus ETF, continues to generate outsized percentage headlines in its lending data — but the underlying story remains one of a structurally uncrowded, lightly traded wrapper with little genuine short conviction.

The short interest figure deserves immediate context. SI landed at roughly 0.03% of the free float on September 22 — around 1,780 shares in absolute terms. That number has swung wildly: up more than 500% over the past month, down 67% in a single session on September 22, after a spike on September 21 and another on September 16. None of this reflects directional trading pressure. With positions measured in the low thousands of shares, these moves are statistical noise around a near-zero base. The borrow market corroborates that reading — availability is running at roughly 444%, meaning there are nearly four-and-a-half shares available to lend for every one currently borrowed. The lending pool is deep and largely untouched.

Cost to borrow has continued its downward drift noted in the previous note. It now sits at 1.20%, down sharply from the 4.96% peak touched on September 1 and well below mid-September levels above 2.5%. The ORTEX short score has nudged higher — from around 26-27 through most of the past two weeks to 32.8 on September 22 — but that remains a moderate reading with no sign of short-seller conviction building in a meaningful way. Options data is stale and not actionable.

The fund itself is broadly flat. CSM closed at $88.55 on September 22, up 1.65% on the week but essentially unchanged over the past month. The dividend history shows quarterly distributions, with the most recent payment of $0.23 per share in June 2026 — slightly above the March 2026 payment of $0.21. That steady income profile, combined with the fund's systematic long-short strategy tilting toward analyst-upgraded large-caps, keeps the investor base oriented toward long-term holders rather than tactical traders.

What to watch: any sustained pickup in cost to borrow or a drop in availability below the 200% threshold would signal genuine demand for borrow in a name that has shown essentially none — and would mark a meaningful shift from the pattern of the past several months.