SHY: how its history is extended
SHY returns from its first trading day; earlier history from VGSH, then VFISX. (represented by the treas_short asset chain before its own history)
Kind
Backfill chain
Extended from
1991-10-29
Through
2026-09-14
Sources
SHY → VGSH → VFISX
Validation at each junction
| Real series | Stands in before it | Real data from | Overlap (years) | Monthly correlation | Return gap (pp/yr) | Gate |
|---|---|---|---|---|---|---|
| SHY | VGSH | 2002-07-30 | 16.75 | 0.9885 | -0.076 | pass (bars: corr ≥ 0.9, |gap| ≤ 1.0pp) |
| VGSH | VFISX | 2009-11-23 | 16.74 | 0.9641 | 0.009 | 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.