CoreWeave Short Book Grows for the Fourth Straight Week

Short sellers have added to their CoreWeave position for the fourth consecutive week, with ORTEX now estimating 87.7 million shares short as of October 27. That represents 22.7% of the free float, up from 73.0 million shares a month ago, a 27.7% increase in borrowed stock over thirty days. The week-on-week build was 20.2%, the largest single-week jump in the period tracked.

The borrow market has tightened alongside the position growth but has not yet reached extreme levels. Availability has dropped sharply, falling from roughly 138% on October 19 to 75% by October 27, meaning lenders now have about three shares available for every four already lent out. Cost to borrow has risen 23% week-on-week to 0.57%, still low in absolute terms but now at its highest point in the trailing 30-day window. The ORTEX short score has climbed steadily, reaching 67.7 on October 27 from 64.9 the week prior, placing short-side positioning in the seventh percentile of the full universe. Options positioning has also shifted. The put/call ratio of 0.87 runs above its 20-day average of 0.78, a reading roughly 1.2 standard deviations elevated, consistent with demand for downside protection rising through October. The PCR is still below its 52-week high of 1.00, so caution is elevated rather than extreme.

The analyst community is pulling in two directions. Goldman Sachs upgraded the stock to Buy on October 19, setting a $106 target, the first bellwether upgrade during a selloff that at its worst took the stock down more than 30% from September highs. Goldman's entry represents a reset of expectations rather than a conviction call, acknowledging that the repricing has already done significant work. Since then, UBS cut its target to $105 from $120 while keeping Buy, and Morgan Stanley trimmed to $70 from $99 while holding Equal-Weight, its most bearish reading from a major house. The Street-wide consensus remains Buy with 23 firms constructive, and a mean target of $134.58, though the cluster of recent reductions tells a more cautious story. The most relevant bear case is structural: Microsoft accounted for roughly 67% of 2025 revenue, and EBITDA covers interest expense only 2.2 times, leaving limited cushion if rate conditions shift or that customer concentration unwinds.

The insider picture is consistent with a planned-sale programme, not discretionary conviction. The CFO and Chief Revenue Officer each sold shares on October 12 and 13 under pre-arranged 10b5-1 plans, at prices between $77 and $81. The 90-day net value across all insider transactions is negative $51 million. These are mechanical sales, not open-market decisions, but the pace and timing add to the backdrop of a stock under pressure well before Tuesday's 7.9% single-session bounce to $59.57. BlackRock added 14.7 million shares in Q3 according to the latest institutional filings, the largest net increase of any major holder in the period, while founders Michael Intrator and Brannin McBee trimmed positions modestly. NVIDIA, listed via GPU Ventures at 11.5% per its most recent 13G/A, has not adjusted its disclosed stake.

After August's Q2 print the stock jumped 22% on the day and added another 5.6% over the following week, CRWV's only earnings reaction in the ORTEX history. November 10 is the next scheduled event. The question entering that date is whether the short book, now at a post-IPO high in share terms, begins to cover into a potential positive catalyst, or whether the leverage and concentration concerns the bears have spent October pricing in dominate the reaction regardless of the headline numbers.