Finding the cheapest online trading may not be as easy as you would guess.  You will need to have a strong understanding of all the fees and commissions you are likely to face with your account.  Trading accounts often come with a wide array of charges to your account.  Make sure you look at all the fees that you are likely to incur when comparing brokers. 

One of the biggest fees you are likely to pay is the commission per trade.  Most brokers will not have a flat fee but instead charge you based upon a variety of factors including the volume of shares traded, the type of stock being traded, the total number of shares traded, the balance in your account, and the way that the trade is made.  Many times online brokers will offer you the ability to speak with a broker and make a trade over the phone for a higher commission. 

Another thing to look at when choosing the cheapest online trading company is the account minimums that they require.  Some brokers will not have minimums associated with their accounts with others will require that you keep a certain amount on deposit in order to trade.  The minimums can be as little as $100 or as high as $3,000.  While this is not money you are spending it is money that you will need to come up with in order to begin trading. 

Many brokers will charge monthly or quarterly maintenance fees in addition to the commission.  Some brokers will be willing to waive these fees for clients who maintain a high balance.  Also be aware of any cancellation fees which are charged by the brokers.  Hopefully you will not be cancelling your account any time soon but it is good to know what it will cost you if you need to cancel for whatever reason.