In short: #TrumpBTCTreasury means that Trump is moving towards Bitcoin in two ways:

* His company (TMTG) is buying Bitcoin for its treasury, aiming for financial protection and using it in transactions.

* Trump is calling for the establishment of a national American Bitcoin reserve to enhance America's leadership in cryptocurrencies and protect its economy.

In summary: Trump sees Bitcoin as a strategic asset for his companies and possibly as a national reserve.