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?
Easy.
If bitcoin is going down, he is probably buying the fucking dip. Following his tweets I can say he is pro bitcoin. It is natural to think that he is buying every dip there is and there will be. Other than that, I don't think there is another way to verify this.
Why do you care anyway? There are bigger market movers than Saylor.