If by fees, you mean brokerage commissions, there arre no legal maximums or miniums. Commissions are negoiable with all firms though most firms have a minium transaction charge. As a general rule, you ought not to be chraged more than 3% of the principle involved in a transaction. Unless, there is a minimum commission charged for very small orders. Most places $35 to $50 on trades under a $1000.