September 2026 ASX Index Rebalance Sees Multiple Additions and Removals Across Benchmarks
S&P Dow Jones Indices has announced its September 2026 quarterly rebalance for the S&P/ASX indices, with significant reshuffling across major benchmarks effective before market open on September 21.
- No change to S&P/ASX 20 Index constituents
- Mineral Resources and NEXTDC added to S&P/ASX 50
- Multiple additions and removals across S&P/ASX 100, 200, 300, and All Ordinaries
- Adisyn Limited joins the S&P/ASX All Technology Index
- Changes effective prior to trading on September 21, 2026
Key Shifts in ASX 50 Highlight Mining and Tech Moves
The September quarterly rebalance by S&P Dow Jones Indices brings fresh dynamics to Australia’s top 50 stocks, notably welcoming Mineral Resources Limited (ASX:MIN) and NEXTDC Limited into the S&ASX 50, while bidding farewell to stalwarts Cochlear and WiseTech Global. This reshuffle signals a subtle tilt towards mining and data centre infrastructure, sectors that have been in focus amid evolving market conditions.
Mineral Resources, which has recently demonstrated operational strength and balance sheet improvements, will now feature in the ASX 50, reflecting its growing market significance. NEXTDC’s inclusion underscores the rising prominence of data centre operators in the Australian market.
Broader Index Adjustments Spread Across Market Tiers
The S&ASX 100 sees Codan Limited added, with Atlas Arteria exiting, while the S&ASX 200 experiences a more extensive reshuffle. Five companies including Elsight and Sunrise Energy Metals join, offset by removals such as GrainCorp and Pantoro Gold. The S&ASX 300 index undergoes its largest turnover, with 15 additions including Core Lithium and Echo IQ, alongside 15 removals like G8 Education and Immutep.
These changes reflect ongoing sector rotations and company performances across the mid and small cap spectrum. Investors tracking these benchmarks will need to adjust portfolios accordingly ahead of the September 21 effective date.
All Ordinaries and Technology Indices See Significant Refresh
The All Ordinaries index experiences a substantial update with over 30 companies added, ranging from Alligator Energy to Waratah Minerals, while a similar number depart, including Audinate Group and Webjet Group. Meanwhile, the S&ASX All Technology Index adds Adisyn Limited, marking a modest but notable expansion in tech sector representation.
These moves could influence liquidity and valuation trends for affected stocks, particularly those newly included or removed from widely followed indices.
Implementation and Market Impact Considerations
All changes will take effect prior to the open on Monday, September 21, 2026. Index share data adjustments for capped and equal weighted indices will follow on September 11. Market participants, including index funds and ETFs, will be recalibrating holdings to mirror these updates.
While the announcement does not provide explicit rationale or financial impact estimates, such quarterly rebalances are routine yet critical for maintaining accurate market benchmarks. The inclusion of Mineral Resources into the ASX 50, given its recent operational milestones and financial strengthening, may attract renewed investor attention ahead of the rebalance.
Bottom Line?
Investors should monitor the September 21 rebalance effects on liquidity and sector weightings, especially with mining and tech stocks gaining prominence.
Questions in the middle?
- How will Mineral Resources’ addition to the ASX 50 influence its stock performance and investor interest?
- What impact will the removal of established names like Cochlear and WiseTech have on their share liquidity?
- Could the broader reshuffle signal shifting sector momentum ahead of year-end market positioning?
