MUU Options Traders Turn Defensive as Borrow Stays Pinned at 11%

The put/call ratio on MUU jumped to 0.79 on June 24 — a z-score of 2.39 against the 20-day mean. That is the most defensive options positioning in two weeks. It arrives as the borrow market snaps back to its tightest levels since mid-June.

Borrow Tightened Again Overnight

Availability collapsed back to 11.3% on June 24. That means roughly one share remains available for every nine already lent out. The pool had briefly loosened — availability reached 38% on June 23 — but that reprieve lasted a single session.

The borrow has been critically constrained for most of the past month. Availability was literally zero on multiple sessions between June 9 and June 15. The current 11% reading is tight, but not the floor this market has already seen.

Cost to borrow sits at 4.23% — down from above 7% in mid-May, and off 18% versus last week. Lower cost with near-zero availability is a structural quirk of this borrow pool: supply is so thin that price discovery may lag physical constraint.

Short Interest: A Volatile Week

SI hit 12.6% of free float on June 24, up 33% in a single day. That sounds alarming. But zoom out one week and shorts are still down 32% over the same window.

The pattern since early June has been persistent covering interrupted by single-session spikes. SI peaked above 20% of float in early June. It has trended lower since, despite intraday volatility. The short score has followed: it fell from 65.5 in mid-June to 54.9 as of June 23 — a meaningful retreat from the high-conviction bear reading of two weeks ago.

Options Positioning Shifts

The PCR move to 0.79 breaks sharply from recent baseline. The 20-day mean was 0.64. Standard deviation is 0.064. At 2.39 standard deviations above average, the options market is sending a different signal than it was even 48 hours ago — when the PCR was 0.55.

The 52-week PCR high is 0.97, reached in May. Current levels are elevated but not at the extreme. The direction of travel over a single session is the notable fact here.

Data Summary

• SI % of Free Float: 12.6% (June 24), up 33% on the day, down 32% on the week
• Borrow availability: 11.3% — very tight (one share per nine already lent)
• Cost to borrow: 4.23%, down 18% week-on-week
• Short score: 54.9 (June 23), down from 65.5 two weeks ago
• Put/call ratio: 0.79 (z-score: +2.39 vs 20-day mean of 0.64)
• Price: $902.10, down 0.6% on the day, up 69% over the past month