Where AI capex meets the tightest physical supply limit: HBM/DRAM, NAND and data-center disk. Sold-out capacity, multi-year supply agreements and an oligopoly structure concentrate pricing power in the memory makers — the shortage trade inside the AI buildout, tracked separately from the optical chain so each supply cycle reads clean.
Follow the theme against the wider market.
Series before each basket's creation date are a backtest of the membership as of creation; live tracking starts at creation.
| Return | 1 day | 5 days | 20 days | 60 days | MTD | YTD | 1 year |
|---|---|---|---|---|---|---|---|
| Basket | -6.7% | -16.8% | -22.9% | -23.8% | -25.1% | +221.1% | +370.7% |
| vs S&P 500 | -5.6% | -15.2% | -23.0% | -26.5% | -25.3% | +185.8% | +307.9% |
1y · 2025-10-16 – 2026-10-16 · 252 / 252 sessions
Basket total returns · Annualized using 252 trading sessions · 0% risk-free rate and downside target. As of 2026-10-16 · close.
Sharpe: average daily simple return divided by its sample standard deviation, multiplied by √252. The risk-free rate is assumed to be 0%; this is not a cash-adjusted ratio.
Sortino: average daily simple return divided by downside deviation, multiplied by √252. Downside deviation is the square root of the average squared shortfall below 0%, counting all sessions, including zeros for gains.
Historical volatility: √(252 × average squared daily log return), matching the Vol page’s realized-volatility convention. This differs from the sample standard deviation used in Sharpe.
Each period requires complete history and at least 5 sessions. MTD and YTD follow the calendar; 1y is 252 sessions. Missing data or an undefined ratio displays — with a reason. Short periods can produce unstable ratios; intraday snapshots include a partial session. History before this basket’s creation is backtested. If a new basket has no stored daily return series yet, estimates from its rounded published chart levels are marked ≈.
Current members and the reasoning behind each inclusion. Returns are for individual holdings.
| Why it’s included | Added | |||||
|---|---|---|---|---|---|---|
| MUMicron Technology | HBM/DRAM oligopoly member — the tightest supply in the AI bill of materials | -5.6% | -14.6% | -13.5% | +208.1% | 2026-07-21 |
| WDCWestern Digital | Data-center hard drives post-spin — exabyte demand outrunning supply | -6.9% | -16.4% | -24.8% | +92.9% | 2026-07-21 |
| STXSeagate Technology | The HDD duopoly's other half; HAMR density lead | -7.5% | -18.4% | -25.5% | +132.8% | 2026-07-21 |
| SNDKSandisk Corporation | NAND pure play (the WDC flash spin-off); enterprise SSD demand from AI data pipelines | -6.8% | -17.9% | -27.5% | +447.4% | 2026-07-21 |
Partial price histories: SNDK from 2025-02-13.
Equal-weighted; monthly rebalance, buy-and-hold between rebalances; dated membership changes reset the target weights.
Tracked since 2026-07-21. Membership decisions are documented below.
Read the methodology →Basket returns include dividends. “vs S&P 500” compares the basket’s compounded growth with the benchmark’s. Green means positive; red means negative.
Cross-checked against SMH. Daily return correlation: 0.75 across 1707 sessions. semiconductor proxy: MU is a top-10 holding but the fund is dominated by logic and foundry — a loose fit by design
Split out of the combined Optics & Memory basket on its creation day, before it shipped a live series: memory/storage and optics are distinct supply cycles (DRAM/NAND pricing vs transceiver unit growth) and deserve separate monitors. Members and rationales carried over unchanged — MU, SNDK, WDC, STX, plus RMBS in the FW 3000. The Asia memory majors (Samsung, SK Hynix, Kioxia) and offshore-domiciled SIMO remain outside the US-listed universes. Reference stays SMH, with the same known dilution.