Mamiya-OP: Borrow Costs Double as Earnings Loom

Mamiya-OP heads into its May 13 earnings with one of the most expensive borrow markets it has seen in months — and a stock already down 13% in April.

The lending market tells the most charged story this week. Cost to borrow has roughly doubled over the past month, climbing from around 2.8% in late February to 6.6% now. The move is not smooth: CTB briefly touched 10.3% on March 26 and 9.5% on April 21 before easing back, suggesting repeated spikes of demand rather than a single directional shift. Borrow availability has tightened sharply alongside this — the lending pool is nearly exhausted, with availability running at roughly 6% of outstanding loans. That means only one share remains available for every sixteen already borrowed, close to the tightest level of the past year. The ORTEX utilization rank places Mamiya-OP in the 2nd percentile of its universe — almost no breathing room left in the lending pool.

Short interest itself is modest in absolute terms, but the direction is hard to ignore. SI climbed steadily from 0.6% of the free float in mid-March to just over 1.0% by late April — a roughly 60% increase in six weeks. On the latest reading, around 47,600 shares are estimated short against a free float of just under 4.7 million. For a small, illiquid TSE-listed leisure products name, even a relatively small absolute short position creates outsized friction in the borrow market. That dynamic explains the CTB volatility: supply is thin, demand has grown, and any additional short-side activity immediately pressures rates.

The ownership structure amplifies the tightness. Data-Art, Inc. holds 38.5% of shares and Ambition Capital LLP a further 13.6% — together they control more than half the company. Ambition added 841,200 shares as of its last filing in November 2025. With two anchored holders controlling the majority of the register, the effective free float available for lending is structurally constrained. Dimensional Fund Advisors and WisdomTree are minor holders, with Dimensional adding a small position as recently as January 2026.

The earnings backdrop sharpens the tension further. The last two confirmed earnings prints — both tied to the February 2026 release — produced a one-day move of -9.4% and a five-day decline of roughly 11%. The preceding print in November 2025 was nearly identical: -9.4% on day one, -9.6% over five days. That kind of consistent post-earnings drawdown, combined with a stock already under pressure (down 13% over the past month to ¥1,281), gives short sellers a clear directional thesis. The ORTEX short score has nudged above 50 and drifted higher throughout April, crossing from 49.5 on April 15 to 50.4 by April 28 — a modest but steady build.

Correlated peers on the TSE had a similar week: 7832 fell nearly 5% over the same period, while 7865 was roughly flat. RGR, the US firearms maker that sits as a moderate correlation peer, managed a 2.5% gain — the only notable outlier in the group. Mamiya-OP's -1.6% weekly move looks broadly in line with the domestic leisure-products complex, suggesting macro Japan rather than company-specific flow drove most of the weekly price action.

The May 13 earnings print is now the clear focal point: whether CTB continues its volatile pattern or stabilises, and whether the stock repeats its consistent post-release weakness, will define the trade for the weeks ahead.