SharkWater Trading  •  Data Centers • Insider Filings Nebius Insider Tape Sorted: One 500,000 Share Plan Sale and Four Routine Ones October 10, 2026 Bottom Line Up Front Five Nebius (Nasdaq: NBIS) insider sales hit EDGAR in the first week of October. Only one is large. COO Ophir Nave sold 500,000 shares on October 5, 2026 for roughly $117.8 million (desk calculation) under a 10b5-1 plan adopted May 22, 2026. The CEO, the Chief Infrastructure Officer and the CTO together sold 81,414 shares on October 1 at $234.16, about $19.1 million, and each Form 4 says the sale only covered tax on vesting units and was automatic. A director's trust sold 50 shares. Strip out the routine paper and the tape is one seller, and his plan says it is finished. Who Sold, and Why Seller Date Shares Price Type per filing Nave, COO 10/5/2026 500,000 $235.53 avg (desk calc) 10b5-1 plan, adopted 5/22/2026 Volozh, CEO 10/1/2026 37,778 $234.16 Tax withholding, automatic Korolenko, Chief Infrastructure Officer 10/1/2026 29,090 $234.16 Tax withholding, automatic Shtan, CTO 10/1/2026 14,546 $234.16 Tax withholding, automatic Boynton trust, director 9/29/2026 50 $235.01 10b5-1 plan, adopted 3/6/2026 Source: Nebius Group N.V. Forms 4 and Forms 144 on EDGAR: accessions 0001513845-26-000126 (Nave), -000120 (Volozh), -000118 (Boynton), -000122 (Shtan), -000124 (Korolenko, role per its Form 4), and Form 144 0001950047-26-010048 (Nave) and 0001950047-26-009868 (Boynton trust). Nave average price and all dollar totals computed by this desk from the filed rows. Sizing the Pile Nave's sale is 6.1 times the three tax sales combined. Against the 238,400,165 shares outstanding cited on the Nave Form 144, his sale is about 0.21 percent of the company and the tax sales together are about 0.03 percent. Neither moves the float. The tax sales are mechanical. Each Form 4 says the shares were sold when restricted share units vested, solely to cover estimated withholding, under automatic sale instructions in the unit agreement and not as a discretionary trade. After the sale the CEO still held 785,236 shares directly. The Boynton trust is a drip, not a surprise. Its September 29 Form 144 lists three earlier plan sales in the prior three months: 6,958 shares on July 15, 5,296 on August 14 and 6,364 on September 15, 18,618 shares for $4,144,629.26 in total. The 50 share sale is a stub on a monthly schedule. Five boats left the harbor this week. Three were ferries running on a timetable, one was a rowboat on its usual route, and one was a trawler hauling out half its direct catch. What Is Still Open Nave's Form 4 remarks state that no further sales will be made under his plan. That is the issuer's own filing, but a new plan can be adopted later, and the filing does not say when. This desk has no verified NBIS price or volume series for the week, so any market reaction to this selling is NOT VERIFIED. The Goldman Sachs 13G/A cut covered here yesterday sits alongside this paper but is a separate and unrelated filer. A correction to this desk's October 7 post: it gave October 7 as the Nave Form 4 filing date. The EDGAR feed shows filing date October 6, 2026, and the filing is signed October 6. The Bull Case Mostly mechanical. Four of five sales are tax cover or a standing monthly plan. None of them is a discretionary call on the stock. The big seller is done. Nave's remarks say no further sales under the May 22 plan, so the overhang from that plan is cleared. Small against the share count. All five sales together are about 0.24 percent of shares outstanding (desk arithmetic). The Bear Case The COO is the one with a choice. A plan is chosen in advance, and he chose to sell 500,000 shares, about 52 percent of his direct holding by the Form 4 balances. A new plan is one filing away. The remarks close this plan. They do not rule out the next one. Stacked on the Goldman cut. The bank's reported stake fell 43.6 percent between two 13G/A event dates. Different filers, same two weeks of supply. The SharkWater Take I have written about this tape for four straight days, and today's reading is the least alarming one. When the paper is sorted, one executive made a real sale and the rest is payroll mechanics. Nave's plan is closed, and that matters more to me than the headline dollar figure. The open item is the Goldman cut, which is flow I cannot explain. I do not have an edge on insider filings alone, and I will not invent one. I want a verified price series and the next 13G event date before NBIS gets a trade idea from me. Tight lines, SharkWater Educational and informational purposes only. Not personalized investment advice. All figures sourced as noted and accurate as of publication. The author may hold positions in securities discussed. Do your own work.