IEF: how its history is extended
IEF returns from its first trading day; earlier history from VGIT, then VFITX, then DGS5.CM. (represented by the treas_int asset chain before its own history)
Kind
Backfill chain
Extended from
1962-01-03
Through
2026-09-14
Sources
IEF → VGIT → VFITX → DGS5.CM
Validation at each junction
| Real series | Stands in before it | Real data from | Overlap (years) | Monthly correlation | Return gap (pp/yr) | Gate |
|---|---|---|---|---|---|---|
| IEF | VGIT | 2002-07-30 | 16.81 | 0.9818 | 0.232 | pass (bars: corr ≥ 0.9, |gap| ≤ 1.0pp) |
| VGIT | VFITX | 2009-11-23 | 16.78 | 0.9942 | -0.027 | pass (bars: corr ≥ 0.9, |gap| ≤ 1.0pp) |
| VFITX | DGS5.CM | 1991-10-28 | 34.85 | 0.971 | 0.692 | 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.