Michael Saylor buying $500m or even a billion with his strategy.
How to know when has he entered in the buying spree by looking at the price movements or charts?
I am not familiar with Michael Saylor and his bags as well, But I can give an answer to your question anyway.
And my response is no one knows who's selling or buying in the actual trade. This is the reason why all traders
are anonymous. All we can see is the Txid and the address from the place it came from and to the destination
address too.