Index Rebalance Calendar
Every scheduled reconstitution and rebalance that moves passive money, September 2026 through the January 2027 commodity roll. Dates come from published index-provider rules and announcements; estimates are marked as such.
#All upcoming events
| Date | Event | What happens | Impact |
|---|---|---|---|
| Fri Sep 4 | S&P 500 quarterly announcement | Adds/deletes and share updates published for the September rebalance (~$27T tracking S&P DJI indices). | HIGH |
| Fri Sep 4 | S&P/ASX quarterly announcement | ASX 200/300 September changes announced; September is Australia’s biggest flow event (annual IWF review; ~A$2.5B est. trading). | MED |
| Fri Sep 4 | Morningstar (ex-CRSP) ranking day | First-Friday ranking for the September reconstitution of the indexes behind VTI and 12 other Vanguard funds (>$3T tracking). | HIGH |
| ~Sep 7–8 | Nikkei 225 autumn review results | Semiannual review announcement (max 3 changes), effective Oct 1. | MED |
| Wed Sep 16 – Tue Sep 22 | Morningstar (ex-CRSP) transition window | Five-day staggered transition, ~20% of the trade per day — designed to blunt front-running. | HIGH |
| Fri Sep 18 | S&P 500 quarterly rebalance + quad witching | Effective after the close, alongside MidCap 400/SmallCap 600 changes and Select Sector cap checks. | CRITICAL |
| Fri Sep 18 | European & global third-Friday stack | DAX family, STOXX Europe 600 quarterly, EURO STOXX 50 annual, SMI annual (Sandoz in / Swisscom out), FTSE/JSE full review — all implemented at this close. | HIGH |
| Fri Sep 18 | S&P/ASX 200 effective | September changes effective after the Sydney close; live Sep 21. | MED |
| Mon Sep 21 | FTSE GEIS semi-annual review effective | Greece promoted to Developed (single tranche); Vietnam begins Secondary-Emerging entry (tranche 1 of 4). FTSE 100/250 quarterly changes also live. | HIGH |
| Wed Sep 23 | Morningstar (ex-CRSP) reconstitution effective | New index compositions live at the open, per the published transitional calendar. | HIGH |
| Wed Sep 30 | Nifty 50 semi-annual change effective | BSE Ltd in / Wipro out (~$0.6–0.7B one-way), via NSE’s new closing auction session. | MED |
| Wed Sep 30 | Bond index month-end | Bloomberg Agg / ICE / iBoxx / JPM EM month-end rebalance; FTSE WGBI Korea phase-in tranche 7 of 8. | MED |
| Thu Oct 1 | Nikkei 225 triple event | Autumn review effective + Advantest cap ratio cut 0.9→0.8 (est. ¥300–420B one-day sell) + new 7-sector classification goes live. | HIGH |
| Wed Oct 7 | TOPIX reform: first review results | JPX posts the first Next-Gen TOPIX periodic review — the start of the ~1,700 → ~1,200 constituent cut. | HIGH |
| Fri Oct 30 | Russell December-recon rank day | Market-cap cut-off for the first-ever December reconstitution. Watch the banding math from here. | HIGH |
| Fri Oct 30 | TOPIX first Next-Gen rebalance | Stage 1 of 8 quarterly phase-out steps (JPX estimates ~¥400B of flow on ~¥83T tracked). | HIGH |
| Fri Oct 30 | Crypto triple-stack | CoinDesk 20 quarterly reconstitution effective 4pm ET, on the same day as CME last-Friday options expiry and the bond month-end (WGBI Korea final tranche). | MED |
| ~Late Oct/early Nov | 2027 commodity index weights | BCOM and S&P GSCI announce 2027 target weights (2026 precedent: Oct 30 / Nov 6 announcements). | MED |
| Wed Nov 11 | MSCI November review announcement | Quarterly add/delete lists for ACWI/World/EM published (watch the digital-asset-treasury exclusion consultation outcome). | HIGH |
| Fri Nov 13 | Russell indicative lists | Preliminary December-recon add/delete files published; query period runs to Nov 27, lockdown Nov 30. | MED |
| Tue Dec 1 | MSCI review effective | November changes live at the open; Nasdaq Crypto Index also reconstitutes Dec 1. | CRITICAL |
| Fri Dec 11 | First-ever December Russell reconstitution | Effective after the close, live Mon Dec 14. Size-rule changes only (banding applies). The headline new event of 2026 — ~$12.2T benchmarked. | CRITICAL |
| Fri Dec 11 | KOSPI 200 semi-annual change | December review effective around the futures-expiry window (exact day pending KRX confirmation). | MED |
| Fri Dec 18 | S&P December stack + quad witching | S&P 500 quarterly rebalance plus the annual style-index reconstitution at the same close. | CRITICAL |
| Mon Dec 21 | Nasdaq-100 annual reconstitution | Effective at the open (reference date: last trading day of November) — first annual recon under the new May 2026 rulebook. FTSE GEIS December quarterly also live. | CRITICAL |
| Jan 8–14, 2027 | S&P GSCI January roll | 2027 weights implemented across the 5th–9th business days at 20%/day. | MED |
| Jan 11–15, 2027 | BCOM January roll | 2027 target weights implemented over the 5-day roll (~$109B tracking the family). | MED |
| Fri Jan 29, 2027 | Bond & crypto month-end stack | JPM GBI-EM country cap cut 10%→9% takes effect; CoinDesk 20 quarterly reconstitution on the same close. | MED |
#The recurring clocks
- S&P 500 / MidCap / SmallCap: quarterly, effective after the third-Friday close of Mar/Jun/Sep/Dec; announced ~2 weeks prior.
- Russell US: semi-annual from 2026 — June (full reconstitution, rank day Apr 30) and December (size rules, rank day Oct 30).
- Nasdaq-100: annual reconstitution in December plus quarterly rank-based reviews (outside top 125 = out) in Mar/Jun/Sep.
- MSCI: quarterly reviews announced ~mid Feb/May/Aug/Nov, effective the following month-start.
- FTSE GEIS: semi-annual Mar/Sep reviews (third-Friday close) plus Jun/Dec quarterlies.
- Morningstar (ex-CRSP): quarterly — first-Friday ranking, then a five-day staggered transition ending the week after the third Friday.
- Bond indexes (Bloomberg Agg, ICE, iBoxx, JPM): every month-end; Bloomberg now locks membership two business days before month-end.
- Commodities (GSCI, BCOM): annual reweights announced late Oct/early Nov, implemented in the January roll; monthly rolls on the 5th–9th business days.
- Crypto (CoinDesk 20, Nasdaq Crypto): CD20 quarterly at the last business day of Jan/Apr/Jul/Oct (announced 4 weeks ahead); NCI quarterly at the first business day of Mar/Jun/Sep/Dec (announced 15 calendar days ahead).
Sources: index-provider methodology documents, published review calendars, and provider announcements, compiled September 2026. Flow figures marked “est.” are estimates. This page is educational information, not investment advice.