If fund managing cryptocurrencies, or big crypto exchange would implement facebook token - token like tether but backed not by USD but by facebook shares. We will be able to invest in facebook on binance using eth/bitcoin/usdt or even $ in future. What about tokenizing whole NYSE, german DAX, NIKKEI, everything ... even polish WIG (all stocks, indeks, materials etc). Stock by stock. We will be able to invest in every asset by buying simple token on crypto exchange by univesal currency - bitcoin.
Some services have tried to simulate that using crypto-backed contract for difference (CFD) schemes. Unfortunately, you need to be a licensed broker-dealer to do it legally. 1Broker got shut down by the SEC a few months ago for letting people bet on stocks with BTC collateral.
I think we'll see what you're talking about in the next 5-10 years: sanctioned equity tokenization where licensed broker-dealers are selling tokens to investors instead of fly-by-night altcoin exchanges. I think that was Circle's plan when they acquired Poloniex.