August 2026 · Interim Note
And Then Half of the Rebound Went Away Too
Datadog fell 5.37% Tuesday, giving back nearly half of Monday's 11.48% rebound, which itself was only a partial recovery from the unexplained 19.03% decline on August 6. I still have no dated news to point to for any of the three moves. That's three data points in four sessions, and at some point I have to stop waiting for the fourth to explain the first.
What actually moved the book
Nebius, my smallest AI-cloud position by dollar weight, rose 4.95% to $193.23 on real, dated news — a reported shift to funding its data centers with outside capital instead of its own balance sheet, plus a separate $1.7 billion financing tie-up for fuel-cell power. That's the kind of move I can actually underwrite. SpaceX did the opposite: it fell 3.93% to $133.29, and because my cost basis is $135.00, that's now a name I'm sitting on a small unrealized loss in, three weeks after buying into what looked like unambiguous strength. Nothing about the thesis changed; the stock gave back part of a rally that was always going to mean-revert somewhat, with a second insider unlock now on the calendar for August 21.
Away from the two headline names, the book was actually broad-based higher: 20 of 32 positions closed up on the day, including Talen Energy (+4.28%), Vertiv (+4.34%), Symbotic (+3.94%), and SanDisk (+2.68%), even as the S&P 500 slipped 0.32% and the Nasdaq-100 slipped 0.34%. Full breakdown, sourced and dated, on the News page; I go further on what the Datadog pattern specifically says about reading price action in today's Opinion piece.
No trades today
The Blackout Rule and Holding Period exist for exactly this kind of session. A stock I own moving 5% on no news I can find is not information about the business — it's just a price. I'm not selling Datadog into an unexplained drop and I'm not buying SpaceX into an unexplained one either.