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Index change event
S&P index changes, effective 21 September 2026
The September rebalance moved 33 companies across the S&P 100, 500, MidCap 400 and SmallCap 600. Nine of them stayed in the family and only changed index.
Announced
2026-09-04
Effective
September 20, 2026 at 5:00:00 PM
Indexes Affected
4
What happened to the prices
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The SmallCap 600 changed most: 10 in, 10 out.
Four names joined the S&P 100 and four left it.
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The changes, index by index
An empty cell means the company was not in the S&P family before, or left it.
S&P 500
Company | Ticker | Source Index | Final Index | Effective Date |
|---|---|---|---|---|
Bloom Energy | BE | S&P 500 | 09/21/2026 | |
Everpure | P | S&P MidCap 400 | S&P 500 | 09/21/2026 |
Illumina | ILMN | S&P MidCap 400 | S&P 500 | 09/21/2026 |
S&P MidCap 400
Company | Ticker | Source Index | Final Index | Effective Date |
|---|---|---|---|---|
AGNC Investment | AGNC | S&P MidCap 400 | 09/21/2026 | |
Brinker Intl | EAT | S&P SmallCap 600 | S&P MidCap 400 | 09/21/2026 |
Corcept Therapeutics | CORT | S&P SmallCap 600 | S&P MidCap 400 | 09/21/2026 |
HubSpot | HUBS | S&P MidCap 400 | 09/21/2026 |
S&P SmallCap 600
Company | Ticker | Source Index | Final Index | Effective Date |
|---|---|---|---|---|
AXT | AXTI | S&P SmallCap 600 | 09/21/2026 | |
Arcutis Biotherapeutics | ARQT | S&P SmallCap 600 | 09/21/2026 | |
AtriCure | ATRC | S&P SmallCap 600 | 09/21/2026 | |
Boston Beer | SAM | S&P MidCap 400 | S&P SmallCap 600 | 09/21/2026 |
Builders FirstSource | BLDR | S&P 500 | S&P SmallCap 600 | 09/21/2026 |
Capri Holdings | CPRI | S&P MidCap 400 | S&P SmallCap 600 | 09/21/2026 |
Delek US Holdings | DK | S&P SmallCap 600 | 09/21/2026 | |
Herc Holdings | HRI | S&P SmallCap 600 | 09/21/2026 | |
Molson Coors Beverage | TAP | S&P 500 | S&P SmallCap 600 | 09/21/2026 |
The Trade Desk | TTD | S&P 500 | S&P SmallCap 600 | 09/21/2026 |
S&P 100
Company | Ticker | Source Index | Final Index | Effective Date |
|---|---|---|---|---|
Arista Networks | ANET | S&P 100 | 09/21/2026 | |
Dell Technologies | DELL | S&P 100 | 09/21/2026 | |
Palo Alto Networks | PANW | S&P 100 | 09/21/2026 | |
Sandisk | SNDK | S&P 100 | 09/21/2026 |
Price reaction
The close price is the last price before the announcement. All percentages are measured from the open price after the announcement.
Additions
Company | Ticker | Close Price | Open Price at Announcement | % Change +5 min | % Change +30 min | % Change at 20:00 Hrs | % Highest Change by Next Day Close |
|---|---|---|---|---|---|---|---|
Arista Networks | ANET | 193.78 | 193.71 | +0.41% | +0.02% | +0.25% | +3.59% |
Dell Technologies | DELL | 524.14 | 522.58 | -0.04% | -0.00% | +0.00% | +3.04% |
Palo Alto Networks | PANW | 333.26 | 334.83 | -0.47% | -0.31% | -0.37% | +1.36% |
Sandisk | SNDK | 1740.00 | 1735.92 | -0.05% | -0.16% | -0.12% | +4.49% |
Bloom Energy | BE | 252.87 | 250.50 | +8.66% | +7.42% | +6.24% | +13.31% |
Everpure | P | 99.51 | 100.00 | +2.00% | +2.02% | +1.05% | +3.65% |
Illumina | ILMN | 218.22 | 218.21 | +1.59% | +2.20% | +0.82% | +3.01% |
AGNC Investment | AGNC | 10.65 | 10.69 | +1.03% | +0.70% | +0.75% | +2.71% |
Brinker Intl | EAT | 230.22 | 230.22 | +0.00% | +0.00% | +0.41% | +1.64% |
Corcept Therapeutics | CORT | 111.62 | 111.48 | -1.33% | -1.33% | +2.03% | +3.79% |
HubSpot | HUBS | 247.60 | 249.99 | +4.00% | +3.00% | +2.78% | +4.80% |
AXT | AXTI | 61.64 | 61.49 | +0.52% | +2.88% | +2.63% | +14.80% |
Arcutis Biotherapeutics | ARQT | 23.90 | 24.25 | +1.48% | +1.92% | -1.03% | +3.59% |
AtriCure | ATRC | 51.52 | 52.27 | +1.19% | +1.19% | +1.63% | +6.60% |
Boston Beer | SAM | 168.78 | 172.94 | -0.14% | -1.64% | +0.57% | +1.02% |
Builders FirstSource | BLDR | 65.79 | 64.74 | +0.40% | +2.91% | +1.62% | +2.91% |
Capri Holdings | CPRI | 13.56 | 13.80 | -0.51% | -0.51% | -2.14% | +1.52% |
Delek US Holdings | DK | 71.86 | 72.31 | +3.39% | +4.26% | +2.48% | +6.67% |
Herc Holdings | HRI | 140.92 | 143.60 | +1.19% | +1.16% | -1.87% | +6.84% |
Molson Coors Beverage | TAP | 40.50 | 41.00 | +0.00% | -1.15% | -1.15% | +0.66% |
The Trade Desk | TTD | 14.43 | 14.41 | +0.00% | +0.00% | +4.79% | +4.79% |
Deletions
Company | Ticker | Close Price | Open Price at Announcement | % Change +5 min | % Change +30 min | % Change at 20:00 Hrs | % Highest Change by Next Day Close |
|---|---|---|---|---|---|---|---|
Colgate-Palmolive | CL | 88.77 | 88.77 | +0.00% | +0.11% | +0.09% | +0.11% |
Honeywell Aerospace | HONA | 161.01 | 161.00 | +0.00% | +0.00% | -4.78% | +0.35% |
NIKE | NKE | 38.40 | 38.42 | -0.00% | +0.08% | +0.01% | +1.47% |
Simon Property Group | SPG | 209.44 | 209.44 | +0.00% | +0.57% | -0.10% | +1.49% |
Amerisafe | AMSF | 25.99 | 25.71 | +1.09% | +1.09% | +0.00% | +1.09% |
Cogent Communications Holdings | CCOI | 10.05 | 9.97 | +1.30% | +0.80% | -0.40% | +10.33% |
Franklin BSP Realty Trust | FBRT | 8.59 | 8.59 | -1.16% | -1.16% | -1.16% | +0.00% |
Matthews Intl | MATW | 21.13 | 20.88 | +1.05% | +1.05% | +0.00% | +1.05% |
N-able | NABL | 4.06 | 4.06 | -1.23% | -1.23% | -1.23% | +0.00% |
NexPoint Residential Trust | NXRT | 23.78 | 23.57 | -0.30% | -0.30% | +0.81% | +0.81% |
Shenandoah Telecommunications | SHEN | 12.59 | 12.45 | -0.16% | +1.12% | -0.08% | +1.23% |
Verra Mobility | VRRM | 4.07 | 4.07 | +0.00% | +0.00% | +0.25% | +1.97% |
Not a Investment Advice
This page is research about past price behaviour. It is not a recommendation to buy or sell.
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