I think there are several ways for investments to come to or exist on Ethereum:
1、Peg: Where the underlying is held in a traditional repository and a token is issued to represent that asset.
2、Native: where the blockchain has its own asset (ether, bitcoin, etc).
3、Smart contract: where the asset (equity, fixed income, etc.) is directly issued on the blockchain i.e. not posted in traditional ledgers (Fedwire securities, Fedwire funds, DTCC, or issuer shareholder ledger) but posted on the blockchain. Somehow the issuer needs to be legally obligated to service these contracts like in traditional legal systems.
4、Derivatives: where contracts are entered between parties on the blockchain that obligates both parties to pay for future results of some underlying event or value (swaps, options, futures, etc.)