In general, if you look at this chart, you can see a clear buying strategy, they buy little during strong market movements (whether it be an increase or a fall) and make large purchases during price consolidations.
10-15M might seems like alot of money but its pretty niche compared to their bigger purchases and those small purchases was kinda like sending messages to the mass that Microstrategy will keep on buying and accumulating bitcoin. Pretty smart move from Saylor, didnt he tweet them up everytime he made that small purchases?
Well bitcoin hits 51k right now, so MSTR lets see if Saylor is going to tweet another purchase huh