Bid-ask spreads refer to the fact that at any given time, you have to pay more to buy a stock than to sell it. Treasury Bill A debt instrument of the United States government that is due within one year. Turnover Refers to the level of discretionary trading activity in a portfolio. In practice, turnover is measured as the minimum of sales and purchased divided by the average value in the account. This measure is designed to ignore the affect of purchases and sales that result from the inflow and outflow of capital from the investor.
Discretionary trading occurs in order to generate higher returns.
An investor sells one security in order to buy another he or she expects to perform better than the one sold. Non-discretionary trading occurs unavoidably. For example, you may liquidate a security in order to withdraw funds to pay for a child's college education. Venture Capital Funds invested in new companies. The yield on a bond making the assumption that the security is held to call.