S&P index changes, effective 9 and 10 February 2026

Ciena moved up from the MidCap 400 to the S&P 500, and Arrowhead Pharmaceuticals moved up from the SmallCap 600 to the MidCap 400.

Announced

2026-02-04

Effective

February 8, 2026 at 4:00:00 PM

Indexes Affected

What happened to the prices

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Two companies moved up one index each.

Dayforce left the S&P 500 and did not join another index.

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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
Ciena	CIEN	S&P MidCap 400	S&P 500	02/09/2026

Company	Ticker	Source Index	Final Index	Effective Date
Arrowhead Pharmaceuticals	ARWR	S&P SmallCap 600	S&P MidCap 400	02/09/2026

Company	Ticker	Source Index	Final Index	Effective Date
ADT	ADT		S&P SmallCap 600	02/09/2026
OneSpaWorld Holdings	OSW		S&P SmallCap 600	02/10/2026

The close price is the last price before the announcement. All percentages are measured from the open price after the announcement.

Company	Ticker	Close Price	% Highest Change by Next Day Close
Ciena	CIEN	253.50	+2.96%
Arrowhead Pharmaceuticals	ARWR	68.06	+2.14%
ADT	ADT	7.75	+3.74%
OneSpaWorld Holdings	OSW	20.07	+11.51%

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
Dayforce	DAY
Dynavax Technologies	DVAX

This page is research about past price behaviour. It is not a recommendation to buy or sell.