The investor is legally responsible to document all trade information.

The investor initiates the transaction and creates the order to Buy/Sell. 

The investor is the beneficiary of a transaction (he receives the asset, or the money)

The Investor can be a company, a mutual fund, or a hedge fund, a public institution or a private invidual.

The investor is responsible for clearing and settlement of his transactions.

The investor decides to Buy or Sell a financial instrument.