DSP. A SEC-regulated program which enables a company to sell shares of stock directly to investors, rather than through a broker, enabling the investors to avoid paying a commission. DSPs are a good way to invest small amounts since you don't even have to be a current shareholder in order to purchase the shares. The company will not charge you a commission, but they may charge you a small fee in order to set up a stock purchase account. Direct Stock Purchase Plans are not related to Directed Share Programs (which have the same acronym, DSP).