Index change event
S&P SmallCap 600 Additions & Index Changes: GPOR & MBGL – 26th June 2026
On 26 June 2026, S&P Dow Jones Indices announced 4 index changes affecting 4 companies in the S&P SmallCap 600. The most notable move was Gulfport Energy joining the S&P SmallCap 600.
Announced
2026-06-26
Effective
June 30, 2026 at 5:00:00 PM
Indexes Affected
S&P SmallCap 600
4
Index Changes in Total
2
Additions
2
Deletions
0
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 +7.35%, against +1.15% for the 2 deletions. The largest mover was Mobility Global, with a peak of +14.29%. The moves are measured from the first extended-hours price after the announcement, except for 2 names with no recorded trade after 17:15 ET, measured from the 16:00 ET close.
Gulfport Energy went against the other addition: its next-day open was -0.26% from the post-announcement price, while the 2 additions averaged +2.25%.
In Short
4 index changes: 2 additions and 2 deletions.
No company moved between indexes, and the changes took effect on 2 dates.
Largest peak move: Mobility Global, +14.29% 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 |
|---|---|---|---|---|
Company | Ticker | Source Index | Final Index | Effective Date |
|---|---|---|---|---|
S&P SmallCap 600 Additions: Gulfport Energy (GPOR) and Mobility Global (MBGL)
2 companies joined the S&P SmallCap 600 and 2 left, effective 1 and 2 July 2026. Gulfport Energy and Mobility Global are new to the S&P family and Core Laboratories and Select Medical Holdings left the S&P family. The 2 additions with price data peaked at an average of +7.35% by the next day's close, led by Mobility Global at +14.29%.
Company | Ticker | Source Index | Final Index | Effective Date |
|---|---|---|---|---|
Gulfport Energy | GPOR | S&P SmallCap 600 | 07/01/2026 | |
Mobility Global | MBGL | S&P SmallCap 600 | 07/02/2026 |
Company | Ticker | Source Index | Final Index | Effective Date |
|---|---|---|---|---|
Price reaction
The close price is the last price before the announcement. Percentages are measured from the open price after the announcement, or from the close for a company with no price after it.
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 |
|---|---|---|---|---|---|---|---|---|---|---|
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 |
|---|---|---|---|---|---|---|---|---|---|---|
Gulfport Energy | GPOR | S&P SmallCap 600 | 162.87 | 167.44 | -0.16% | +0.03% | +0.03% | -0.26% | +0.42% | |
Mobility Global | MBGL | S&P SmallCap 600 | 21.00 | +4.76% | +14.29% |
Not a Investment Advice
This page is research about past price behaviour. It is not a recommendation to buy or sell.