December 2025 ASX Rebalance Adds 15 Companies, Drops 12 Across Major Indices
S&P Dow Jones Indices has revealed its December 2025 quarterly rebalance, introducing notable changes across major ASX indices that could reshape market dynamics ahead of the new year.
- Lynas Rare Earths and Washington H. Soul Pattinson added to S&P/ASX 50
- Multiple mining and tech firms join S&P/ASX 200 and All Technology indices
- No changes to the S&P/ASX 20 index this quarter
- Removals include Amcor, Mirvac, Reece, and Reliance Worldwide
- Changes effective before market open on December 22, 2025
Quarterly Rebalance Overview
On December 5, 2025, S&P Dow Jones Indices announced the latest quarterly rebalance of the S&P/ASX indices, set to take effect prior to trading on December 22. This routine review adjusts the composition of key Australian stock indices, reflecting shifts in market capitalisation and liquidity. While the S&P/ASX 20 index remains unchanged, significant movements are evident in the broader indices.
Notable Additions and Removals
The S&P/ASX 50 index welcomes Lynas Rare Earths Limited and Washington H. Soul Pattinson and Company Limited, signaling a boost for sectors tied to rare earths and diversified investments. Conversely, stalwarts like Amcor PLC and Mirvac Group exit this tier, potentially impacting their index-linked fund demand.
Further down the market cap ladder, the S&P/ASX 100 sees additions such as CMM Eagers Limited and Capricorn Automotive Metals Limited, while Reece Limited and Reliance Worldwide Corporation Limited are removed. These shifts highlight evolving investor focus within mid-cap stocks.
Expanding the S&P/ASX 200 and Technology Indices
The S&P/ASX 200 index experiences a flurry of changes, with Aussie Broadband Limited, NexGen Energy (Canada) Limited, and several mining companies like Ora Banda Mining and Resolute Mining joining the fold. Meanwhile, companies such as Bapcor Limited and IPH Limited are removed, reflecting changing market valuations and sector rotations.
In the technology space, the All Technology Index adds emerging players including Acusensus Limited, Artrya Limited, Cogstate Limited, and Kinatico Limited. This infusion of fresh tech names underscores the sector's dynamic nature and investor appetite for innovation.
Market Implications and Next Steps
Index rebalances often trigger shifts in trading volumes and share prices as index funds adjust their holdings to mirror the updated compositions. Investors should watch closely how these inclusions and exclusions influence liquidity and valuation trends, especially for newly added companies that may see increased demand.
While the announcement does not detail the rationale behind each change, the quarterly review remains a critical mechanism ensuring indices accurately represent the evolving Australian equity landscape.
Bottom Line?
As December 22 approaches, market watchers will keenly observe how these index changes ripple through trading floors and portfolios.
Questions in the middle?
- How will the inclusion of Lynas Rare Earths and Washington H. Soul Pattinson affect their stock performance?
- What are the underlying factors driving removals of established companies like Amcor and Mirvac?
- Will the new tech additions to the All Technology Index attract sustained investor interest?
