MSTR will definitely NOT be joining the S&P500 this session. This is public information
Can you link a public source?
The official S&P Dow Jones Indices press release from August 25, 2025, announced that Interactive Brokers Group would be joining the S&P 500, with NO mention of MicroStrategy, which strongly signals its exclusion from being included.
Not that something can't change
aat the very last minute...but it doesn't look like it's going to happen.
One key for Strategy was that BTC kept its head about $98.8k which it has, so there may be a 'bit' of magic in the air, but at the time of the official S&P Dow Jones Indices press release it did not look promising for Strategy to be included...