Mizuho Shorts Pile In as Borrow Pool Hits Empty

MFG availability has now collapsed to 2.5%. Every share in the lending pool is out on loan. Short interest jumped 8.8% in a single day — and options traders are adding protection simultaneously.

This is the third tightening episode in four weeks. Each prior dip toward zero was followed by a partial recovery. This time, short sellers are still adding actively despite having almost nowhere left to borrow from.

Short Interest Accelerates Into a Closed Market

Short interest hit 7.3 million shares on June 25. That is up 13.2% over the week. A month ago, borrowed shares sat at 4.3 million. The position has grown 70% in under 30 days.

What makes this notable is the context. Availability is at 2.5% — meaning fewer than one share remains for every 39 already borrowed. In mid-May, availability was above 112%. The borrowable pool has effectively been emptied.

Previous coverage noted the pattern: availability collapsed to 2.4% on June 15, recovered briefly to nearly 20%, then fell again. It is now at a new cycle low. Each recovery has been shallower. The current level is the tightest since data began tracking this year.

Options Confirm Defensive Shift

The put-call ratio reached 0.76 on June 25. That sits 2.04 standard deviations above the 20-day mean of 0.72. The PCR has drifted steadily higher since late May, when it was near 0.67.

The move is not dramatic in absolute terms — the 52-week high is 1.28. But the pace of the shift is consistent with the rest of the picture. Options traders are hedging more aggressively as the stock dropped 6.9% over the past week.

Cost to Borrow Edges Back

One thing has changed since the June 23 article: cost to borrow pulled back slightly. CTB was 1.68% last Wednesday. It has since eased to 1.46%. That is still up 3% over the past month and well above May levels. The retreat does not signal relief — it more likely reflects lenders adjusting rates as the pool empties and fewer new borrows are being initiated at the margin.

Earnings are scheduled for July 30. That gives roughly five weeks for the current positioning to resolve, one way or another.

Data Summary

• Availability: 2.5% — 52-week low
• Short interest: 7.3M shares, +8.8% day-on-day, +13.2% week-on-week
• Cost to borrow: 1.46%, up ~3% over 30 days
• Put-call ratio: 0.76, +2.04 standard deviations above 20-day mean
• Stock: down 6.9% over the past week, $9.59 close June 25
• Next earnings: July 30, 2026