SWTSX: how its history is extended
SWTSX returns from its first trading day; earlier history from VTI, then VTSMX. (represented by the us_total asset chain before its own history)
Kind
Backfill chain
Extended from
1992-04-28
Through
2026-09-11
Sources
SWTSX → VTI → VTSMX
Validation at each junction
| Real series | Stands in before it | Real data from | Overlap (years) | Monthly correlation | Return gap (pp/yr) | Gate |
|---|---|---|---|---|---|---|
| SWTSX | VTI | 1999-05-28 | 25.24 | 0.998 | -0.016 | pass (bars: corr ≥ 0.9, |gap| ≤ 1.0pp) |
| VTI | VTSMX | 2001-06-15 | 25.22 | 0.9994 | 0.112 | pass (bars: corr ≥ 0.9, |gap| ≤ 1.0pp) |
Figures on this page are computed from the data store when the page renders; the gate is re-checked every time an extension is used. Method: the lab's tracking standard, lab.data.chains.