Retail Giant Overstock to Issue its Own Stock on Blockchain PlatformFor its tØ stock, Bagley said Overstock is using a permissioned ledger to manage shares, but that transactions will be batched and hashed against the bitcoin blockchain for additional transparency.
http://www.coindesk.com/overstock-blockchain-stock/some mix of permissioned ledger and bitcoin but a start

I don't know how that works but if this is the case then I'm all ears. I'd love it if stock markets were open 24 hours/day but I'm sure it doesn't exactly mean that.