US Discount Brokerages 

Interactive Brokers - finished in first place with a 4.5 star rating by Barron's magazine in their 2014 analysis of online brokerages.  They provide access to over 100 markets in 24 countries. They provide both fixed and tiered pricing which may result in a very low price for a low quantity of shares (i.e. - under 1000 shares). It appears that larger orders may be more expensive (i.e. over 15,000 shares) than some of the competition.

Place Trade - they scored a 4.5 star rating on the Barron's magazine 2014 survey and ended up in 2nd place. Clients with under $2000 balance will be charged $20 for inactivity. For accounts greater than $100,000 there is no inactivity charge. There are various other charges if there is not a sufficient amount of activity so clients should read the fine print.  

Trade Monster- this discount brokerage was launched in 2008 and is based out of Chicago. They charge $4.95 for online trades. It is owned by OH Acquisitions LLC. There is a $2000 minimum opening balance. There is no indication of any maintenance fees for inactivity. They finished in 3rd placein the Barron's 2014 survey of online brokerages with 4.5 stars. 

TD Ameritrade - the discount brokerage for TD Ameritrade. This is the combined company between TD Waterhouse and Ameritrade. One of the market leaders for discount brokerages in terms of market share. They have partial ownership by TD Bank. They charge $9.99 per online trade and there is no minimum balance to receive this price. There is no minimum balance in this account and there are no maintenance fees. They scored very high on the Barron's online brokerage survey for 2014 with a 4.5 star rating and ended up in 4th place. 

Scott Trade - is a privately owned discount brokerage. They  charge $7 per online trade for stocks over $1. There is an initial balance required of $500 and there are no maintenance fees. Scott Trade provides S&P Capital IQ research reports. 

Charles Schwab - is one of the market leader for discount brokerages. They charge $8.95 per online trade for stocks. The minimum balance is $1000. There are no maintenance fees. Charles Schwab also has some portfolio solutions whereby investors can get professional management. 

Sharebuilder - is part of Capital One. The charge for online equity trades is $9.95. There are no account minimums. They provide research from Thomson Reuters, Sabrient, S&P Capital IQ, The Street Ratings and Zacks Investment Research.

Merrill Edge - offers online stock and ETF trades for $6.95. This brokerage is owned by Bank of America.  

E*Trade - large discount brokerage company that has been around for over twenty years. There are over $189 billion dollars in customer assets worldwide and over 4.3 million customer accounts. E*Trade provides S&P research and Thomson Reuters research for stocks and Morningstar research for ETFs and Mutual Funds. The costs for online stock trades are $9.99.  There are a number of extra fees that seem unusual such as a $2 fee for each paper statement. See their website for details.