Microstrategy

So I keep seeing media about all the BTC Mr Saylor and co have supposedly purchased. How can we verify any of this on-chain -- "pooled with others @ some insto, trust me bro" is the wrong answer. SEC filings and random articles aren't right either. Anyone can literally say anything. Normally I wouldn't even care, but their claims are being pushed so incredibly hard in public that I think we're going to need some verifiable proof; like on the public ledger.