An Investment Agreement Letter is a written agreement that outlines the terms of an investment between two parties. It is used to document the details of an investment, such as the amount being invested, the timeframe for return on investment, and any additional investment rights or privileges. It also serves to protect both parties if the investment doesn’t go as planned. Investing in a business venture shouldn’t be taken lightly – put the safety of your money first and make sure to sign an Investment Agreement Letter to ensure your gains and guard against losses.