T1 Index · The Trillion Dollar Club · equal-weight · base 2025-12-30 = 100
The T1 Index
One rule: a company joins the day it first closes at a $1 trillion market cap, and never leaves. The T1 is the equal-weight index of that club — 12 members were already in by the 2025-12-30 base, 4 crossed during 2026. Each addition counts only from the day it joined the club, never backdated — so the index tracks what the club itself earned, not the run that got a stock into it.
152 points · since 2025-12-30
Members
| Company | Status | In since | Market cap | Weight | Return since base | In-club return |
|---|---|---|---|---|---|---|
| MU Micron | 2026 addition | May 11, 2026 | $1.17T | 6.1% | +200.1% | +10.4% |
| 000660.KS SK Hynix | 2026 addition | Apr 27, 2026 | $1.19T | 5.7% | +123.7% | +15.3% |
| 005930.KS Samsung Electronics | 2026 addition | Jan 16, 2026 | $1.63T | 6.1% | +97.5% | +62.9% |
| TSM TSMC | Founding | 2025-12-30 | $2.26T | 6.3% | +40.8% | — |
| AVGO Broadcom | Founding | 2025-12-30 | $2.12T | 6.4% | +22.7% | — |
| NVDA Nvidia | Founding | 2025-12-30 | $5.43T | 6.6% | +19.6% | — |
| AMZN Amazon | Founding | 2025-12-30 | $2.81T | 6.2% | +18.0% | — |
| AAPL Apple | Founding | 2025-12-30 | $4.50T | 6.3% | +15.0% | — |
| 2222.SR Saudi Aramco | Founding | 2025-12-30 | $1.71T | 6.2% | +15.0% | — |
| GOOGL Alphabet | Founding | 2025-12-30 | $4.55T | 5.9% | +13.0% | — |
| LLY Eli Lilly | Founding | 2025-12-30 | $965B | 6.6% | +10.2% | — |
| BRK-B Berkshire Hathaway | 2026 addition | Aug 4, 2026 | $1.01T | 6.3% | +3.6% | +0.9% |
| MSFT Microsoft | Founding | 2025-12-30 | $3.42T | 6.3% | +3.0% | — |
| WMT Walmart | Founding | 2025-12-30 | $912B | 6.3% | +0.3% | — |
| META Meta Platforms | Founding | 2025-12-30 | $1.52T | 6.3% | -10.9% | — |
| TSLA Tesla | Founding | 2025-12-30 | $1.56T | 6.3% | -27.7% | — |
"Return since base" measures the move since 2025-12-30; for 2026 additions this includes the run before they joined the club (context only). "In-club return" is what the index actually counts — the move since the stock crossed $1T.
Methodology
Membership. A stock is a member from the first day it closes at or above $1,000,000,000,000 (one trillion USD) market cap, and membership is permanent — Eli Lilly and Walmart crossed earlier and trade below $1T today, but stay in the club. The index starts on the last trading day of 2025 (2025-12-30), so the 12 stocks already in the club then are the founding members; later crossers are added on their crossing date.
Weighting. Equal weight, reset to 1/N only on each $1T crossing — when a new member joins the club, every position is rebalanced back to equal weight; between crossings the basket is left to drift, so a name that runs carries a heavier weight until the club next changes. The reset funds the new member by trimming the others, so the level stays continuous — no cash is added, and the return needs no time-weighting adjustment. Returns are USD total return; the US members price from EODHD, the three internationals (Samsung, SK Hynix in KRW; Saudi Aramco SAR-pegged) from their home markets converted to USD at the daily rate.
Additions enter honestly. A 2026 addition joins at the prevailing index level on its crossing date and contributes only from that day forward — the index never backdates a stock's pre-membership run. That is why Samsung's +46% in-club return counts, not the larger move that carried it over $1T.
Index reading is a diary entry on our process. Closelook publishes research, not investment advice.