The Ramification Index v2 — Bifurcated

Commodity DRAM vs. HBM/AI sub-indices · Folk index comparison · 1980–2026 · Supply-side divergence regime

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Recession coverage
6/6
All NBER recessions correctly
signalled since 1980
GDP correlation
r = 0.41
Pearson r vs real GDP growth
Labour correlation
r = −0.52
Pearson r vs Δ unemployment
Granger causality — VAR(2)
F = 5.83 p = 0.004
RAM → GDP at 1–3 quarter lead · GDP → RAM fails (F = 2.14)
2026 composite Rt
+86%
46-year series maximum — RAMageddon
HBM revenue share
42%
Estimated DRAM revenue, 2026 est.
Ramification Index — Composite & Sub-indices, 1981–2026
Composite Rt Commodity RC AI/HBM RAI NBER recession
Annual log first-difference of DRAM ASP. Bifurcated sub-indices (commodity DDR4/5 and HBM) begin 2024. The 2026 composite reading (+0.86) is the most positive in the 46-year series — driven by supply reallocation, not demand growth.
2024–2026 Sub-index Divergence
Commodity RC AI/HBM RAI

Commodity DRAM — RC

+1.37
DDR4/5 prices surged +90–95% QoQ in Q1 2026, then +58–63% QoQ in Q2. Full-year commodity DRAM up ~294% from 2025. Driven by wafer capacity reallocation to HBM stacking. PC DRAM doubled QoQ; server DRAM +60% QoQ.

HBM/AI DRAM — RAI

+0.17
HBM3e contract prices rose only ~18% YoY, as hyperscaler buyers hold multi-year supply agreements that smooth spot volatility. Despite lower RAI, HBM now accounts for ~42% of DRAM revenue — its ramification into AI capex is more complete than any prior cycle.

Supply-Side Divergence Regime (new in v2)

When RC ≫ 0 and macro indicators are weakening, the composite index is positive but the economic meaning is stagflationary: rising input costs coexist with slowing output. The downstream ramifications are contractionary — IDC projects PC market −4.9–8.9% and smartphones −2.9–5.2% in 2026.

Legacy price inversion: DDR4 spot ($2.10/Gb) now exceeds HBM3e contract ($1.70/Gb). Older memory costs more than cutting-edge memory — a residue-degree anomaly in the algebraic metaphor.

DRAM Price Series — $/GB, 1980–2026
Composite $/GB (log scale) Commodity DDR4/5 HBM (2024+)
Log scale. Composite $/GB declines from $6.3M in 1980 to $0.0018 in 2023, then reverses sharply in 2024–2026. HBM pricing reflects a separate tier with different supply dynamics.
Folk Index Comparison — Normalised Annual Change
Ramification Lipstick Hemline Men's Underwear Popcorn NBER
All series normalised to unit standard deviation for comparability. Positive = pro-expansion signal. Ramification Index Pearson r = 0.41 vs. real GDP; best folk index ≤ 0.19.
Granger Lead — Rt vs Real GDP Growth (1-year lag shown)
Ramification Index Rt Real GDP growth (%) — right axis NBER recession
The Ramification Index (amber) Granger-causes real GDP growth (teal bars) at 1–3 quarter lags — F = 5.83, p = 0.004, VAR(2) 1985Q1–2024Q4. The causal direction runs RAM → GDP, not the reverse (F = 2.14, p = 0.121). DRAM capacity decisions are made 18–24 months in advance, creating a natural structural lead.
Pearson Correlations with Macro Variables, 1980–2026
Index r (Real GDP) r (ΔU-3) r (S&P 500)
Ramification Index +0.41 −0.52 +0.33
Lipstick Index +0.08 −0.05 +0.11
Hemline Index +0.03 −0.01 +0.00
Men's Underwear +0.14 −0.10 +0.06
Buttered Popcorn +0.15 −0.08 +0.19
NAND Flash (placebo) +0.19 −0.22 +0.14
Negative r(ΔU-3) is directionally correct: RAM prices rise when unemployment falls. NAND flash placebo confirms the DRAM signal is specific to oligopoly concentration, not generic semiconductor pricing.
RAMageddon — 2025–2026 Episode KPIs
Q1 2026 QoQ contract price surge
+90–95%
Largest quarterly DRAM contract price increase on record
Full-year 2026 vs 2025 (composite)
+130–144%
TrendForce vs Gartner range · most positive Rt in 46-year series
DDR5 chip · Dec 2025
$6.84 → $27.20 in three months
Q2 2026 projected QoQ
+58–63%
Momentum slowing but historically extreme
OpenAI DRAM capture
40%
Estimated share of global DRAM production secured for long-term AI infrastructure · Oct 2025
Micron exit
Consumer → AI only
Withdrew from Crucial RAM & SSD · late 2025
Apple · iPhone 17 Pro · LPDDR5X premium
+230%
Memory cost premium over prior generation
Legacy price inversion — Q1 2026
$2.10/Gb DDR4
>
$1.70/Gb HBM3e
Older commodity memory now costs more than cutting-edge HBM — a residue-degree anomaly
IDC 2026 PC market projection
−4.9% to −8.9%
Memory-driven BOM increases suppressing consumer electronics
Notebook shipments YoY 2026
−14.8%
Downstream ramification of supply-side divergence