The US isn't a corporation, it doesn't own my productive output, and random UBI recipients never paid for their shares. If you set up a country with this idea

The US isn't a corporation, it doesn't own my productive output, and random UBI recipients never paid for their shares. If you set up a country with this idea from the start (a profit-seeking corporation with transferable shares), it might be a good idea, but probably no net beneficiaries of UBI would have shareholder status.