A change in the margin requirement for a current holding may result in a margin maintenance call on your account. The execution price of a market order may depend on the number of orders ahead of yours. Initial public offerings may be volatile. Large block trades may be executed at different times and at significantly different prices. Changing a market order may result in the execution of duplicate orders.
Limit orders can limit risk.
Telephone and online access during volatile markets. Freeriding is prohibited. A fast market is characterized by heavy trading and highly volatile prices. Potential Risks in a Fast Market Prices and trades move so quickly in a fast market that there can be significant price differences between the quotes you receive one moment and the next. The size of a quote, meaning the number of shares available at a particular price, may change just as quickly.