Russell reconstitution 2026: December dates and rules

The Russell 2000 index of small US companies is about to be rebuilt for the second time this year. Rank day is Friday, Oct 30, 2026: at the close that day, FTSE Russell takes the market snapshot it uses to decide which stocks belong in the Russell 1000, the Russell 2000 and the rest of its US index family. Preliminary lists of additions and deletions come out after the close on Fri, Nov 13, and the changes take effect after the close on Fri, Dec 11. FTSE Russell calls it "the first December reconstitution in more than three decades" (FTSE Russell, Sep 1, 2026).

Through 2025 the Russell US indexes were reconstituted once a year, in June. From 2026 they are rebuilt twice a year, in June and December. This guide sets out the December timeline, why the schedule changed, how a stock gets in or out, and what is different about a December reconstitution. Every rule and date here comes from FTSE Russell's own publications. We have no lists of likely additions or deletions and make no predictions: the official preliminary lists are FTSE Russell's to publish on Nov 13.

When is the Russell reconstitution in December 2026?

Sources: FTSE Russell schedule release (Sep 1, 2026) for the steps; the list-update dates are from FTSE Russell's Oct 26 outlook and its reconstitution hub, checked Oct 30, 2026.

The query period and the lockdown are named in FTSE Russell's public schedule; how each works in detail is set out in its index methodology document, linked from the reconstitution hub. One practical note: Fri, Nov 27, the day after Thanksgiving, is both a list-update day and a shortened session, with US stocks closing at 1:00 pm ET (our market holidays guide has the hours).

The general rule. Russell reconstitution changes take effect after the close on the fourth Friday in June and the second Friday in December, according to FTSE Russell's FAQ. Rank day is the last business day of April for the June reconstitution and the last business day of October for the December one (FTSE Russell, Apr 10, 2026).

What is rank day?

Rank day is the day whose closing data decides membership. FTSE Russell describes it as the day when "eligible US securities are ranked by total market capitalization" (Oct 26 outlook). That snapshot forms the basis for the whole reconstitution: the breakpoint between large and small companies, and which stocks move in, out or between indexes.

Two things follow from that. First, a company's size is measured on rank day, not on the effective day six weeks later. A stock that rises or falls sharply in November doesn't change its ranking. Second, the work that happens between rank day and Dec 11 is about publishing and refining the result. The updated lists, FTSE Russell says, "reflect changes that may occur between rank day and the reconstitution, including eligibility adjustments that affect additions and deletions" (FTSE Russell, describing the June cycle).

Why does the Russell rebalance twice a year now?

The short answer, in FTSE Russell's words: volatility and changing market dynamics. The longer story ran over two years.

• Jan 16, 2025: the announcement. FTSE Russell said the indexes would move to a semiannual schedule in 2026, keeping the fourth Friday in June and adding a second date, the second Friday in November, "contingent on a successful parallel test run in November 2025". It called the decision "based on data analysis and market consultation undertaken in response to the recent evolution of market dynamics and increased volatility". Catherine Yoshimoto, a director of product management at FTSE Russell, pointed to "increased volatility within US equity markets over the past five years, compared to the prior fifteen years" (FTSE Russell).
• November 2025: the parallel run. FTSE Russell ran a full semiannual reconstitution as a test, without changing the live indexes. It reported that the test confirmed "operational readiness" and showed "minimal impact on index characteristics" (FTSE Russell).
• The move from November to December. In the same review, FTSE Russell set the effective date on the second Friday in December instead of November, "based on market feedback indicating sufficient liquidity on the December date". Older pages that still say "November" predate this change.
• Dec 17, 2025: confirmation. FTSE Russell's updated research paper confirmed that the indexes "will move to a semi-annual reconstitution frequency, starting in December 2026" (FTSE Russell).

FTSE Russell describes the goal as helping the indexes "provide accurate market representation while remaining practical performance benchmarks" (Oct 26 outlook). Its own numbers show how fast leadership can turn within a year: the small-cap Russell 2000 did better than the Russell 1000 in the second quarter of 2026, then fell 7.2% in the third quarter while the Russell 1000 returned 1.8%. Over the 12 months to Sep 30, the Russell 2000 was still ahead, at 16.2% against 15.0% (FTSE Russell figures, as of Sep 30, 2026).

It isn't the first time. When the Russell indexes launched in 1984 they were reconstituted quarterly. They moved to a semiannual schedule in 1987 and to an annual one in 1989 (FTSE Russell). FTSE Russell itself calls 2026 a "return" to a semiannual schedule.

How does a stock get into the Russell 2000 or the Russell 1000?

There is no selection committee. "There's no committee deciding who joins. If a company's stock meets the eligibility rules, it qualifies," FTSE Russell writes, adding a footnote that some cases may fall under its policy on expert judgment (FTSE Russell, Apr 10, 2026). That is a real difference from indexes whose membership a committee decides, such as the S&P 500: the Russell indexes follow published rules applied to rank-day data.

The main eligibility tests, as FTSE Russell summarizes them:

• US company. Incorporated, headquartered and listed in the US. Mixed cases go through further checks on where assets and revenue sit.
• Eligible exchange. CBOE, NYSE, NYSE American, NYSE Arca or Nasdaq. Over-the-counter, pink-sheet and bulletin-board stocks don't qualify.
• Price. A close of at least $1.00 on the primary exchange on rank day. Existing members are judged on a 30-day average price instead, to avoid needless turnover.
• Size. Total market capitalization of at least $30 million on rank day.
• Float and voting rights. At least 5% of shares freely tradable, and at least 5% of voting rights held by unrestricted shareholders.
• Structure. Royalty trusts, US limited liability companies, closed-end funds, blank-check companies and SPACs, limited partnerships, ETFs and mutual funds are excluded, and so are preferred shares, warrants, rights and depositary receipts.
• Paperwork. The stock must be listed on rank day, and FTSE Russell must have documents supporting its eligibility on that date.

What are the Russell breakpoints, and how does banding work?

On rank day, every eligible company is ranked by total market capitalization. The largest 4,000 form the Russell 3000E. The largest 1,000 of those become the Russell 1000 (large caps) and the next 2,000 the Russell 2000 (small caps) (FTSE Russell). The market value of the 1,000th company sets the breakpoint between the two. Once a stock is in, its weight uses its investable market cap, after adjusting for shares that aren't freely traded.

Banding stops stocks near the line from flipping back and forth. An existing member moves between the Russell 1000 and Russell 2000 only if its market cap moves more than 2.5% away from the breakpoint, measured in cumulative market-cap percentile. There is no band at the bottom of the Russell 2000 (FTSE Russell).

In dollars, the band is wide. At the June 2026 reconstitution the breakpoint was $5.7 billion, but because of banding the smallest Russell 1000 company was worth $2.7 billion and the largest Russell 2000 company $9.6 billion:

Total market capitalization as of each year's rank day. The breakpoint is the line between the Russell 1000 and the Russell 2000; the smallest Russell 1000 and largest Russell 2000 companies reflect banding. Source: FTSE Russell, reconstitution hub historical table, checked Oct 30, 2026.

The 2026 breakpoint was 24% higher than 2025's, and the whole Russell 3000 was worth $75.6 trillion on the Apr 30 rank day, up 29% from $58.4 trillion a year earlier (FTSE Russell, May 22, 2026). After the June reconstitution, FTSE Russell's hub counts 3,023 stocks in the Russell 3000, 1,027 in the Russell 1000 and 1,996 in the Russell 2000. The counts aren't exactly 1,000 and 2,000 because of banding.

What we don't know yet: the December breakpoint. FTSE Russell says the December review will reassess the size indexes "based on updated market capitalization data, redefining the breakpoints between large-, mid- and small-cap stocks" (Oct 26 outlook). The new figure comes with the preliminary lists on Nov 13, and this guide will add it then. The size rules themselves are the same as in June; FTSE Russell has published no December-only change to them.

How is the December reconstitution different from June?

The size indexes, including the Russell 1000, Russell 2000 and Russell 3000, are rebuilt in full both times. The difference is in the Growth and Value style indexes:

• June: every stock's style is reassessed, and the style indexes are fully reconstituted.
• December: the style indexes are not fully reconstituted. New style probabilities apply only to additions, IPOs included, and to companies moving between the Russell 1000 and the Russell 2000. Companies that stay in the same parent index keep their June 2026 style probabilities (FTSE Russell).

FTSE Russell's reason is turnover: the rule exists "to prevent the extra index turnover that would occur if FTSE Russell updated all stocks' style membership twice a year" (FTSE Russell). It matters because the style indexes carry a large share of the money: FTSE Russell puts them at about two-thirds of all assets benchmarked to a Russell index. In the November 2025 test run, style index turnover was "well below June 2025 levels", FTSE Russell reported.

Two other things are new this December:

• The Russell 9000 Global has its first reconstitution. It combines US, developed ex-US and emerging-market segments of about 3,000 companies each, and the Russell 3000 forms its US segment (Oct 26 outlook).
• The fourth-quarter IPO additions are part of the reconstitution itself, as "new additions, including IPOs" (FTSE Russell).

What happens to IPOs?

FTSE Russell adds eligible IPOs every quarter, in March, June, September and December, so a company that lists between reconstitutions doesn't wait months to join. IPOs big enough to rank in the Russell Top 500, the 500 largest companies in the Russell 3000, take a faster route: they are added after the close on the fifth day after they list (Oct 26 outlook).

IPO additions have picked up. FTSE Russell counts 27 IPO additions to the Russell 2000 in the third quarter of 2026, the most since the fourth quarter of 2021, when there were 40, and 5 to the Russell 1000, the same as in the second quarter.

How much money tracks the Russell indexes?

About $12.2 trillion in investor assets is benchmarked to or invested in products based on the Russell US indexes, FTSE Russell said in May 2026. That is why the effective day draws so much trading: index funds that track the Russell 2000 or Russell 1000 need to hold the new lineup when the indexes change, and many trade at the closing auction that day. At the June 2025 reconstitution, $217.2 billion traded at the close (FTSE Russell): $114.7 billion on the NYSE and a record $102.5 billion on Nasdaq (LSEG). Dec 11 brings the first December reconstitution trade in more than three decades, and how large it will be is unknown until it happens.

Do stock prices move around the reconstitution?

Some trading impact is certain, given the volumes. Whether additions reliably rise and deletions reliably fall is another matter. FTSE Russell's own view, in an LSEG piece from April 2026: "There is undoubtedly some market impact from the index changes; however, the past short-term impact of Russell recon on index constituents' stock prices hasn't reliably followed such a pattern." It attributes that to the long lead time between rank day and the effective day, which lets traders position in advance (LSEG). That is FTSE Russell's assessment, not a finding of ours.

For context, here is what one cycle looked like at the level of two widely traded ETFs: IWM, an ETF that tracks the Russell 2000, and SPY, an ETF that tracks the S&P 500. This is one event in history, not a pattern, and the moves over eight weeks reflect everything that moved markets in that time, not the reconstitution alone.

Closing prices in US dollars on each date in 2026, not adjusted for dividends. IWM tracks the Russell 2000 and SPY the S&P 500; neither is the index itself. Source: StockFit, as of each date's close.

On the effective day, Jun 26, IWM closed 0.31% higher and SPY 0.72% lower. On the first reconstituted day, Jun 29, IWM fell 0.29% and SPY rose 1.65%. From rank day to the effective day, IWM's price rose 7.86% and SPY's 1.44% (price changes only, dividends not included; our calculations from the closes above).

What to watch next

• Fri, Nov 13, after the close: FTSE Russell publishes the preliminary additions and deletions, and with them the December breakpoint between the Russell 1000 and the Russell 2000.
• Nov 20, Nov 27 and Dec 4: updated lists, which can change as eligibility is adjusted.
• Fri, Dec 11, at the close: the changes take effect, and the closing auction carries the trading that follows them.
• Mon, Dec 14: the first session with the reconstituted indexes.

We'll refresh this guide in place on Nov 13 with the official December breakpoint and FTSE Russell's headline figures, and again after Dec 11. The next rank day after that is the last business day of April 2027, for the June 2027 reconstitution. More explainers are in Guides.