Yeah, but is it possible to sell 0 btc to buy 0 xrp?
Pretty sure that just makes him full of shit, if he's claiming to have something and double it daily but really has zero, it's not clever semantics, it's bullshit.
It's a kind of nerd type, mathematically inspired humor: it's vacuously true of his non-existing Bitcoin position that he sold it. It is then vacuously true of his non-existing gains from that sale that he used it to buy Ripple. And so on.
Maybe not your kind of humor, but let's stop calling the old statist geezer a troll. He's just a bit rigid in his thinking
