01-projects/investing/anchors/memory-cycle-v1.1

phase history notes

2026-05-18·investing-anchor·! medium
investinganchorphase-historymemory-cycle-v1.1

Memory cycle v1.1 — phase history notes

Companion to phase-history.csv. First full run, 2026-05-18. This file is the methodology + honest-limits log for the labeled transitions, written so a future re-labeling pass (or /investing:backtest-thesis v2) knows what was strong evidence vs what was inference. Anchors [[2026-05-18-memory-cycle-v1.1]] (supersedes [[2026-05-17-memory-cycle-v1]]).

Methodology used

Mechanical rules applied (where data permits)

Qualitative rules used where mechanical rules fail

Decision rules from thesis applied mechanically

Per phase_definitions in v1.1:

Coverage achieved

Cycle Transitions labeled High-confidence count Medium Low Notes
1997 5 0 4 1 Pre-data era; relying on industry retrospectives + DDR launch + consolidation events
2001 5 0 2 3 Worst-covered cycle; DOJ price-fixing dates are best mechanical anchor we have
2008 7 5 1 0 Best pre-TrendForce cycle (Qimonda bankruptcy = sharp, dateable signal; Micron 10-K data available)
2018 5 4 1 0 Strong vendor financial data (Micron FY18 peak GM) + SK Hynix fab dates available
2022 6 6 0 0 Best-covered cycle; TrendForce monthly + Micron capex-cut + Samsung production-cut all dateable to month
2024-current 5 4 1 0 Live cycle; TrendForce monthly data + smart-money 13F + vendor earnings all available
Total 33 19 (58%) 9 (27%) 5 (15%)

Aggregate: 33 transitions labeled across 6 cycles. 58% high-confidence; 85% high-or-medium confidence. Meets the skill's self-check threshold (>33% high-or-medium, >2/3 not-low).

Top 3 most-confident phase calls

  1. 2022 down-cycle entry (Mar 2022) — TrendForce monthly data shows the regime shift cleanly across Q1 2022; Micron capex cut Sep 2022 confirms; Samsung 50% production cut confirms. Multi-source convergence to within ~1 month.
  2. 2008 down-cycle confirmation (Sep 2008 + Jan 2009) — Qimonda's Jan 2009 bankruptcy is a sharp, dateable consolidation event; cumulative losses Q3 2007-Q4 2008 well-documented in industry retrospectives. The bottom is unambiguous.
  3. 2018 capacity-online + cycle-peak (Jun-Sep 2018) — Micron FY2018 GM peaks at 58.9% (extreme oligopoly pricing) immediately preceded by SK Hynix M15 Cheongju production start; Micron stock peaks ~$64 then falls 56% within months. Classic capacity-online → down-cycle transition with clear vendor-financial trace.

Known gaps + caveats for backtest-v2

Sparse pre-2017 data — handle with skepticism

The 1997 and 2001 cycles have only qualitative evidence (industry retrospectives + DOJ records + consolidation events). A backtest run against these labels should expect ~3-month uncertainty on transition dates and should not place strategy decisions on tight phase boundaries pre-2010. The 2008 cycle is better because Qimonda + Micron 10-K + Elpida bailout dates are sharp, but even there, the recovery-to-demand-recognition transition (~2010-06) is medium-confidence at best.

Hyperscaler-capex anchor unusable pre-2014

The v1.1 thesis uses hyperscaler capex direction as anchor #1 — but hyperscalers (AWS, Azure, GCP, Meta) were not the dominant DRAM demand driver until ~2014-2015. Pre-2014 cycles cannot be re-labeled using this anchor; the labels rely on PC/enterprise demand commentary instead. Implication: cycles 1997, 2001, 2008, and the early phase of 2018 are structurally different from current cycles (different demand driver = different dynamics). A backtest spanning 1997-2026 is implicitly comparing two regimes.

Regime change risk — 2024-current cycle may NOT be cyclical

Per founder's v1.1 framing and the Castellano "HBM Has Broken the Memory Cycle" hypothesis, the AI-driven HBM tightness may be structurally different from prior cycles. Specifically: vendors are pursuing "minimize oversupply risk" capex discipline (Samsung explicit statement, Q1 2026 earnings) rather than the classic build-flood-crash cycle. This means the 2024-current cycle may NOT have a cleanly dateable down-cycle entry coming — if the founder's thesis is right, capacity discipline holds and the next transition is plateau, not crash. The backtest harness should treat the current cycle as a "live, may-not-complete" cycle and not force a synthetic crash date.

TrendForce data starts Feb 2021 — earlier gap

The DRAM-spot CSV nominally claims 2017-2026 coverage in its filename, but the actual data starts Feb 2021. Pre-2021 DRAM-spot labeling relied on retrospective industry sources, not the structured monthly scraper output. If a future re-labeling pass wants tighter 2017-2020 transition dates, scraping TrendForce news archives 2017-2020 or pulling DRAMeXchange historical data would help.

Multiple-raters disagreement: 1-2 months expected, larger for pre-2010

Within 2017-2026 (mechanical rules apply): two researchers using the v1.1 phase_definitions and TrendForce data would agree on transitions to within ~1 month. Within 2008-2016 (vendor 10-K + retrospective sources): ~3-month agreement. Pre-2008: ~6-month agreement is realistic, possibly worse. Backtest sensitivity analysis should test phase-window edges at ±1 month (recent cycles) and ±3 months (older cycles).

Smart-money anchor only goes back to 2024 Q2

The smart-money-watch v0 backfill covers 2024 Q2 - 2026 Q1 (8 quarters). For the 2018 cycle and earlier, smart-money 13F evidence was NOT used as a phase anchor — would require a separate historical 13F backfill (3-5 manager 5-year backfill is the natural next step). For the 2024-current cycle, the 2026 Q1 multi-manager SANDISK + INTEL entries support the demand-recognition phase but are not load-bearing alone.

Phase boundaries are not sharp

This is the deepest honest caveat. Phases are labels imposed on continuous underlying state. The "down-cycle" of 2022 began with first price-down signals Dec 2021, dominated by Mar 2022, was deepest by Q1 2023 (Micron GM -32.7%), and "ended" sometime Jul-Nov 2023. Picking any single transition date is a choice. The CSV picks transitions where the founder's defined mechanical rules from phase_definitions first fire, which is the most defensible default.

What the backtest-v2 should do with this

  1. Use the high-confidence transitions as primary phase boundaries. That's ~19 of the 33 entries. The 5 low-confidence pre-2001 entries are inputs the backtest can choose to fold into adjacent transitions if they're not load-bearing.
  2. Sensitivity-test against ±1 month (recent) / ±3 months (older) windows. If thesis P&L is sensitive to a 1-month phase-boundary shift, the strategy is over-fit to the labels and should be reconsidered.
  3. Treat 1997, 2001 cycles as supplementary, not primary. The 2008, 2018, 2022, and 2024-current cycles are the four with usable mechanical phase boundaries. Backtest performance on those four cycles is the meaningful signal.
  4. Treat 2024-current as a live, may-not-complete cycle. Don't assume a down-cycle transition is coming on a fixed clock. The Castellano/Samsung-discipline hypothesis is that this cycle may stay in Phase 2 plateau structurally longer than prior cycles.

Open follow-ups

Sources used in this labeling pass

Changelog