Index change event
S&P MidCap 400 & SmallCap 600 Additions & Index Changes: STRL & RRR – 6th November 2025
On 6 November 2025, S&P Dow Jones Indices announced 4 index changes affecting 3 companies in the S&P MidCap 400 and S&P SmallCap 600. The most notable move was Sterling Infrastructure joining the S&P MidCap 400 from the S&P SmallCap 600.
Announced
2025-11-06
Effective
November 12, 2025 at 4:00:00 PM
Indexes Affected
S&P MidCap 400, S&P SmallCap 600
4
Index Changes in Total
2
Additions
2
Deletions
1
Companies that changed index
What happened to the prices
By the next day's close, the 2 additions with price data had peaked at an average of +1.52%, against +1.25% for Light & Wonder, the only deletion with price data. The largest mover was Red Rock Resorts, with a peak of +2.28%. The moves are measured from the first extended-hours price after the 17:15 ET announcement.
Red Rock Resorts went against the other addition: its next-day open was +0.85% from the first price after the announcement, while the 2 additions averaged -1.37%.
In Short
4 index changes: 2 additions and 2 deletions.
1 company moved from one S&P index to another, out of 3 in total.
Largest peak move: Red Rock Resorts, +2.28% by the next day's close.
The changes, index by index
An empty cell means the company was not in the S&P family before, or left it.
Company | Ticker | Source Index | Final Index | Effective Date |
|---|---|---|---|---|
S&P MidCap 400 Additions: Sterling Infrastructure (STRL)
1 company joined the S&P MidCap 400 and 1 left, effective 13 November 2025. Sterling Infrastructure moved up from the S&P SmallCap 600 and Light & Wonder left the S&P family. Sterling Infrastructure peaked at +0.77% by the next day's close.
Company | Ticker | Source Index | Final Index | Effective Date |
|---|---|---|---|---|
Sterling Infrastructure | STRL | S&P SmallCap 600 | S&P MidCap 400 | 11/13/2025 |
S&P SmallCap 600 Additions: Red Rock Resorts (RRR)
1 company joined the S&P SmallCap 600 and 1 left, effective 13 November 2025. Red Rock Resorts is new to the S&P family and Sterling Infrastructure moved up to the S&P MidCap 400. Red Rock Resorts peaked at +2.28% by the next day's close.
Company | Ticker | Source Index | Final Index | Effective Date |
|---|---|---|---|---|
Red Rock Resorts | RRR | S&P SmallCap 600 | 11/13/2025 |
Company | Ticker | Source Index | Final Index | Effective Date |
|---|---|---|---|---|
Price reaction
The close price is the last price before the announcement. All percentages are measured from the open price after the announcement.
S&P 500 Additions Changes
Company | Ticker | Source Index | Final Index | Close Price | Open Price at Announcement | % Change +5 min | % Change +30 min | % Change at 20:00 Hrs | % Change by Next Day Open | % Highest Change by Next Day Close |
|---|---|---|---|---|---|---|---|---|---|---|
S&P MidCap 400 Additions Changes
Company | Ticker | Source Index | Final Index | Close Price | Open Price at Announcement | % Change +5 min | % Change +30 min | % Change at 20:00 Hrs | % Change by Next Day Open | % Highest Change by Next Day Close |
|---|---|---|---|---|---|---|---|---|---|---|
Sterling Infrastructure | STRL | S&P SmallCap 600 | S&P MidCap 400 | 388.68 | 389.00 | -1.08% | -2.12% | -0.26% | -3.59% | +0.77% |
S&P SmallCap 600 Additions Changes
Not a Investment Advice
Company | Ticker | Source Index | Final Index | Close Price | Open Price at Announcement | % Change +5 min | % Change +30 min | % Change at 20:00 Hrs | % Change by Next Day Open | % Highest Change by Next Day Close |
|---|---|---|---|---|---|---|---|---|---|---|
Red Rock Resorts | RRR | S&P SmallCap 600 | 55.23 | 56.91 | 0.00% | -0.04% | -0.04% | +0.85% | +2.28% |
Not a Investment Advice
This page is research about past price behaviour. It is not a recommendation to buy or sell.