There are lenders out there that are happy to lend you money (to spend however you wish) by taking unlisted shares as collateral. As I said before, these are usually lenders that are close to both the person taking the loan and the company in which they are securitising the loan against.
It would explain how Nick has afforded these purchases without an exit/sale event, especially given your useful comments re his est. share value based on a $1bn valuation.
