EtfWatch

One calendar for every major index change

When an index committee announces a change, the funds tracking that index must own the new stock by the effective close — whether it is an S&P 500 rebalance in New York, a FTSE 100 quarterly review in London, a DAX 40 change in Frankfurt, or a Nikkei 225 or Hang Seng review in Tokyo and Hong Kong. That forced buying creates a measurable window, and EtfWatch exists to track it across all of these markets in one place.

Last updated 2026-10-03

Who runs EtfWatch

EtfWatch · France

EtfWatch is an independent index-tracking project run from France. It records the constituent changes that index providers announce, the prices around those dates, and how the affected stocks have behaved since — assembled from public sources and checked against each provider's own announcement. It is a reference tool rather than a research house: no paid signals, no positions, and every figure on the site is calculated from recorded market data.

Questions, corrections or removal requests go to contact@etfwatch.app or the contact page.

What we track

Every confirmed addition to the indexes we cover, across the US, Europe and Asia: the announcement date, the effective date, a live countdown while the change is pending, and how the stock performed 1 week, 1 month, 3 months, 6 months and 1 year after inclusion — both in absolute terms and relative to its index.

  • S&P 500

    The 500 large-cap US companies behind SPY, IVV and VOO. Index changes are announced days before they take effect, forcing every tracker to buy at the effective close.

  • Nasdaq-100

    The 100 largest non-financial companies listed on Nasdaq, tracked by QQQ and QQQM. Changes come from the December reconstitution plus intra-year replacements.

  • S&P MidCap 400

    The 400 US mid-cap companies behind MDY and IJH. Stocks are often promoted here on the way to the S&P 500, or demoted out of it.

  • S&P SmallCap 600

    The 600 US small-cap companies behind IJR. Index entries here are frequent and the affected stocks are small enough that index buying moves them.

  • FTSE 100

    The 100 largest companies on the London Stock Exchange, tracked by ISF and VUKE. FTSE Russell reshuffles the index every quarter.

  • DAX 40

    The 40 largest companies on the Frankfurt exchange, tracked by EXS1 and other DAX ETFs. Membership changes come from Deutsche Boerse's quarterly reviews.

  • Nikkei 225

    Japan's price-weighted benchmark of 225 Tokyo-listed companies, tracked by 1321.T and 1330.T. Nikkei Inc. runs a periodic review every October.

  • Hang Seng

    Hong Kong's headline index, tracked by the Tracker Fund (2800.HK). Hang Seng Indexes reviews membership quarterly.

Where the data comes from

No proprietary feed, no paid terminal — two public sources, refreshed by an automated job once a day. Here is exactly what comes from where, so you can check any number yourself.

Index changes — Wikipedia, then the provider's press release
Additions and removals for the S&P 500, S&P MidCap 400, S&P SmallCap 600, Nasdaq-100 and DAX 40 are scraped daily from the “historical components” and component-list pages on English Wikipedia, which track committee announcements closely and cite the original release. Each row keeps its announcement and effective date so it can be matched against the provider newsroom links below. FTSE 100, Nikkei 225 and Hang Seng entries are curated by hand from provider announcements, because no equivalent public change log exists for those indexes.
Prices — Yahoo Finance daily closes
Every return on this site is computed from unadjusted daily closing prices pulled from the public Yahoo Finance chart API, for the stock and for a tracking ETF standing in for its index (SPY, QQQ, MDY, IJR, ISF, EXS1, 1321.T, 2800.HK). Run-up is measured over the 30 sessions into the announcement; post-inclusion returns are measured from the effective-date close. Prices refresh once a day, so intraday moves are not reflected — the timestamp in the header shows how current the data is.
What this means for accuracy
Wikipedia is community-edited and Yahoo closes are unadjusted for splits and dividends in some cases, so treat figures here as a fast read rather than an audited record. Every date on the review calendar links back to the provider newsroom below, so anything that matters can be verified against the original press release. Rumors and speculation are labelled as such and are never mixed into confirmed additions.

Official provider newsrooms

Editorial policy & data methodology

  • Sources. Confirmed additions come from index provider announcements and public constituent change logs (the Wikipedia “historical components” pages for the US and German indexes); prices come from Yahoo Finance daily closes. The provider newsrooms above are linked so every date can be checked at the source.
  • Returns. Run-up is measured over the 30 trading sessions into the announcement date; post-inclusion returns are measured from the effective-date close over 1 week, 1 month, 3 months, 6 months and 1 year — in absolute terms and against a tracking ETF standing in for the index.
  • Rumors. Inclusion rumors are gathered from press coverage and public discussion, are always labelled unconfirmed, and are never counted in the confirmed register. Each rumor keeps its tracked outcome: confirmed, went stale, or didn't happen.
  • Refresh cadence. An automated job refreshes additions and prices once a day; the footer of every page shows the last completed run.
  • Corrections. If a date, sector or return looks wrong, email contact@etfwatch.app or use the contact page with the index, ticker and what you saw. Errors are fixed against the original source, and nothing is invented to fill a gap.

EtfWatch is an independent research tool. Nothing on this site is investment advice, and inclusion speculation is third-party opinion until the index provider confirms it.