Index change event
S&P SmallCap 600 Additions & Index Changes: TENB – 26th August 2026
On 26 August 2026, S&P Dow Jones Indices announced 2 index changes affecting 2 companies in the S&P SmallCap 600. Tenable Holdings replaced Leggett & Platt in the S&P SmallCap 600.
Announced
2026-08-26
Effective
August 30, 2026 at 5:00:00 PM
Indexes Affected
S&P SmallCap 600
2
Index Changes in Total
1
Additions
1
Deletions
0
Companies that changed index
What happened to the prices
By the next day's close, Tenable Holdings, the only addition with price data, had peaked at +7.39%; the deletion, Leggett & Platt, has no next-day prices. The moves are measured from the first extended-hours price after the 17:15 ET announcement.
Only Tenable Holdings has next-day prices, so there is no group to compare it with: it opened the next day at +1.74% from the first price after the announcement.
In Short
2 index changes: 1 addition and 1 deletion.
No company moved from one S&P index to another in this announcement.
Largest peak move: Tenable Holdings, +7.39% 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: Tenable Holdings (TENB)
1 company joined the S&P SmallCap 600 and 1 left, effective 31 August 2026. Tenable Holdings is new to the S&P family and Leggett & Platt left the S&P family. Tenable Holdings peaked at +7.39% by the next day's close.
Company | Ticker | Source Index | Final Index | Effective Date |
|---|---|---|---|---|
Tenable Holdings | TENB | S&P SmallCap 600 | 08/31/2026 |
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 |
|---|---|---|---|---|---|---|---|---|---|---|
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 |
|---|---|---|---|---|---|---|---|---|---|---|
Tenable Holdings | TENB | S&P SmallCap 600 | 33.66 | 35.73 | +0.42% | +0.62% | +1.04% | +1.74% | +7.39% |
Not a Investment Advice
This page is research about past price behaviour. It is not a recommendation to buy or sell.