I'm pretty sure that's why picostocks is structured differently. You are not buying ownership in anything. Picostocks owns all of the assets..."users" are profit sharers.
From the picostocks FAQ:
Do I own assets I buy on PicoStocks?
No. In general, PicoStocks remains the legal owner of the assets. You can sell the asset to other PicoStocks traders to disinvest. However if You own a large fraction of the shares of the asset traded on PicoStocks You can contact the IPO office to discuss the option to delist the shares. PicoStocks can sell shares to other parties as part of it's business model. A 2% fee will apply in this case.