Short Interest & Thesis

Short Interest & Thesis — Sandisk Corp (SNDK)

Bottom line. Reported short interest is decision-relevant but not crowded. FINRA shows 9.21M shares short at May 29, 2026 — 6.23% of float, $15.6B notional, days-to-cover 0.8 — and the share count has roughly doubled since SNDK started trading in February 2025. The crowding test fails: with a 20-day ADV of 11.2M shares and a 0.25–0.27% borrow fee, an entire short book could be covered inside one trading day with no locate friction. What matters is the thesis layer: Citron's public short campaign (Feb 25, 2026), Stan Druckenmiller's Q4 2025 exit, a 22-analyst mean price target below spot, and a $3.3B-vs-$88M imbalance in leveraged-long-vs-inverse ETFs together describe a credible bear narrative that is being crushed by an exponential price move (+5,400% in 16 months). Setup risk runs both ways: gross debt is zero, the buyback is open, and shorts are sitting on large mark-to-market losses while a single supply-side data point — YMTC capacity ramp or Samsung CMB yield — could re-anchor the variant.

Reported short-interest trend — bi-monthly history since spin

The series captures every FINRA settlement date from August 2025 through May 29, 2026.

Two regimes stand out. First, from late September through early February the short book oscillated between 4–6% of float while the stock quadrupled from ~$86 to ~$626 — short adds were repeatedly run over by price. Second, post the Feb 25 Citron note, shares short jumped from 7.62M (2/13) to 8.52M (2/27) and then climbed to a 10.83M peak on April 30 (just before the Q3 FY26 print). That peak — 7.3% of float, $11.9B notional at the time — was unwound by 1.7M shares over the next two weeks as the stock ripped from $1,097 to $1,408. Borrow-and-hope shorts kept being stopped out at higher prices.

Crowding test — easy to short, easy to cover

Three numbers settle the crowding question. (1) Days-to-cover under 1.0 means the entire reported short book trades through the tape in a single session at normal volumes. (2) A 0.25–0.27% borrow fee is general-collateral cheap — there is no locate friction, no rebate pressure, no hard-to-borrow status. (3) Lendable availability of ~2.5–3M shares in mid-June against 9.2M short is mildly tight at the broker-aggregator level, but the borrow fee shows the constraint is not biting. The squeeze risk that retail screens flag on this name is not supported by the structural data.

Borrow fee and lendable supply are nullable indicators from a public lending-data aggregator; treat as directional. The June series shows a modest decline in lendable shares (3.7M → 2.3M) but no fee escalation, consistent with broker-side rebalancing rather than scarcity.

Peer context — SNDK sits mid-pack within storage, high vs general semis

SNDK's 6.23% sits below the spun-off parent (WDC, 9.26%) and well below storage-systems and semi-peripherals peers (NTAP 10.91%, SYNA 11.62%). It is roughly 2x Micron — the closest pure-play memory comparable — and 5x NVIDIA. The data does not flag SNDK as an outlier in either direction; the spread vs MU is the most relevant fact (twice the relative short positioning of the dominant memory bellwether). Peer figures are sourced from a single aggregator; settlement dates may not be perfectly aligned.

Short-thesis ledger — what bears are saying

Leveraged-ETF positioning — long bias dominates the structured-product layer

The 37:1 imbalance is the cleanest single signal of how the structured-product layer is positioned. Inverse demand exists — SNDQ launched only after Q3 FY26 — but the long-leverage pool is roughly two orders of magnitude larger. Daily-reset 2x products are not the same as cash short positions (they rebalance and decay), but the AUM ratio confirms the bear thesis remains a minority view at the leveraged-retail layer.

Short-sale volume — not staged, not a substitute

The staged short-sale-volume table came back empty for SNDK. Daily short-sale volume would have shown the flow of trades marked short on a given session — useful for tape context only, never a stand-in for outstanding reported short interest. Treat this as a documentation gap rather than a thesis fact. The reported FINRA bi-monthly position data above is the correct primary source and is sufficient for crowding and trend judgment.

Public net-short disclosures

Not applicable. SNDK is a US-listed name; the public holder-level net-short disclosure regimes that exist in the UK and parts of the EU do not cover it. No threshold-disclosure rows were staged, and none are expected.

Market setup — how positioning interacts with the next catalysts

The squeeze risk that retail screens habitually attach to this name is not the relevant frame here. Days-to-cover is below 1, borrow is cheap, and lendable supply has covered every fresh short add. The asymmetry that matters for a PM is the opposite: existing shorts are deeply underwater and a strong Q4 print + buyback execution can keep marking them lower, while a single supply-side data point — first sequential ASP deceleration, or a credible YMTC fab milestone — can give the bear thesis the catalyst it has lacked.

Evidence quality