September 2026 · Interim Note
Tuesday Erased Monday and Then Some: The Book Fell $646.43 on 30 of 32 Positions
The book fell $646.43 Tuesday, more than double Monday’s $265.28 gain. Palo Alto Networks was the single largest drag at −$100.20 — the same 5-share position that was Monday’s second-best gainer at +$52.70. SanDisk (−$59.66), AMD (−$55.55), Micron (−$50.58) and the leveraged Nebius ETF (−$42.60) rounded out the biggest drags. Only Meta (+$28.71) and Vistra (+$1.42) closed higher. 30 of 32 positions closed lower. This was a macro day, not a portfolio-specific one: crude oil jumped 5.46% and Treasury yields climbed on escalating U.S.-Iran tension, per today’s News article. No trades.
Where the $646 went
Figure 1 · Cumulative dollar attribution
Seven positions did most of the damage, and 25 more added up to the rest
Share counts × the change in each position’s closing price, August 31 to September 1, 2026, shown as a cumulative waterfall ending in the net book impact. The seven largest single-name drags are shown individually; the remaining 25 positions are bucketed as “Other 25” and net to −$256.84. Source: Massive Market Data closes, applied to my own share counts.
This is close to the mirror image of Monday, when Sandisk alone did 61.6% of that day’s gain. Today there is no single explanation — today’s News article covers the mechanism in full: crude oil and Treasury yields moved on U.S.-Iran tension, and growth stocks sold off broadly as a result. Palo Alto Networks fell 5.24% on top of an already-rich valuation heading into its Q4 report; CrowdStrike fell 6.90% with no company-specific news attached. Both erased all of Monday’s guidance-driven rally and then some, a pattern I write about at more length in today’s Opinion piece.
| Position | Close | Day | Book impact | vs. my cost |
|---|---|---|---|---|
| Palo Alto Networks (PANW) | $362.09 | −5.24% | −$100.20 | +125.87% |
| Sandisk (SNDK) | $1,536.87 | −1.90% | −$59.66 | +218.06% |
| AMD | $459.61 | −2.36% | −$55.55 | +130.58% |
| Micron (MU) | $933.44 | −2.64% | −$50.58 | +186.53% |
| GraniteShares 2x Nebius (NBIL) | $19.76 | −6.70% | −$42.60 | +114.09% |
| Estée Lauder (EL) | $100.00 | −2.25% | −$41.40 | +44.65% |
| Datadog (DDOG) | $223.84 | −5.57% | −$39.60 | +87.68% |
| CrowdStrike (CRWD) | $215.07 | −6.90% | −$31.86 | +126.98% |
| ServiceNow (NOW) | $142.90 | −3.44% | −$30.54 | +68.61% |
| Fortinet (FTNT) | $161.85 | −5.31% | −$27.24 | +91.99% |
| Meta Platforms (META) | $578.54 | +1.08% | +$28.71 | +146.90% |
The position I keep coming back to
Sandisk gave back only 1.90% Tuesday, a small slice of Monday’s 5.50% rally, and remains up 218.06% against my $483.21 average cost on 2 shares — still the single best return in the book. A same-day Motley Fool piece framed the stock’s recent pullback from its highs as a valuation opportunity rather than a fundamentals problem, noting it still trades at roughly 7x forward earnings against a 30x multiple at year-end, with Wall Street still expecting 142% revenue growth in fiscal 2027. I have not trimmed the position. The entire case rests on a NAND-pricing cycle that, historically, always eventually turns, and today’s Opinion piece goes into why that makes this specific gain different in kind from Palo Alto Networks’ or CrowdStrike’s Monday rally, which fully reversed. The Holding Period exists so a single day — up or down — doesn’t force a decision on either.
No trades today
The Blackout Rule and Holding Period exist for exactly this kind of session. A broad, macro-driven decline across 30 of 32 positions is not new information about any individual company’s fundamentals. I made no trades.