Index change event
S&P MidCap 400 & SmallCap 600 Additions & Index Changes: BSY & WU – 1st October 2025
On 1 October 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 Bentley Systems joining the S&P MidCap 400.
Announced
2025-10-01
Effective
October 5, 2025 at 5:00:00 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, Bentley Systems, the only addition with price data, had peaked at +5.84%, against +1.23% for Western Union, the only deletion with price data. The moves are measured from the first extended-hours price after the 17:15 ET announcement.
With one addition and one deletion priced, there is no group to stand out from: Bentley Systems opened the next day at +3.58% and Western Union at +0.99%, both from the first price after the announcement.
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: Bentley Systems, +5.84% 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: Bentley Systems (BSY)
1 company joined the S&P MidCap 400 and 1 left, effective 6 October 2025. Bentley Systems is new to the S&P family and Western Union moved down to the S&P SmallCap 600. Bentley Systems peaked at +5.84% by the next day's close.
Company | Ticker | Source Index | Final Index | Effective Date |
|---|---|---|---|---|
Bentley Systems | BSY | S&P MidCap 400 | 10/06/2025 |
S&P SmallCap 600 Additions: Western Union (WU)
1 company joined the S&P SmallCap 600 and 1 left, effective 6 October 2025. Western Union moved down from the S&P MidCap 400 and Mr. Cooper Group left the S&P family. Western Union peaked at +1.23% by the next day's close.
Company | Ticker | Source Index | Final Index | Effective Date |
|---|---|---|---|---|
Western Union | WU | S&P MidCap 400 | S&P SmallCap 600 | 10/06/2025 |
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 |
|---|---|---|---|---|---|---|---|---|---|---|
Bentley Systems | BSY | S&P MidCap 400 | 52.34 | 53.29 | +3.21% | +1.67% | +5.09% | +3.58% | +5.84% |
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 |
|---|---|---|---|---|---|---|---|---|---|---|
Western Union | WU | S&P MidCap 400 | S&P SmallCap 600 | 8.08 | 8.10 | +0.41% | +0.13% | +0.49% | +0.99% | +1.23% |
Not a Investment Advice
This page is research about past price behaviour. It is not a recommendation to buy or sell.