Overall commission costs can also be affected by new customer promotions. Brokers may give you a chunk of free trades based on your deposit amount. If your deposit gets you a substantial number of free trades, that can write off otherwise higher per-commission costs. Ally Invest offers small incentives for deposits as low as $500. Fidelity Investments, meanwhile, has a higher barrier for entry — it takes a $50,000 deposit, but then you'll get 300 free trades.
In addition to attractive pricing, Ally offers a quality platform that gives you access to the entire universe of stocks and ETFs. Where some discount brokers focus on only one kind of trader (for example, options traders or high-net-worth investors), Ally Invest provides an excellent experience for investors of all kinds. A focus on discounted costs can sometimes be a red flag for quality, but Ally truly delivers with sophisticated calculators, profit-loss estimators, and more. Ally also offers a robust research library that incorporates visual slides and interactive media into its market data.
Thinkorswim is a particular standout in options trading, with options-trading tabs (just click “spread” if you want a spread and “single order” if you want one leg), plus links that explain the strategies on the order page. Its Strategy Roller feature lets investors create custom covered calls and then roll those positions from expiration to expiration.

This is not an offer or solicitation in any jurisdiction where we are not authorized to do business or where such offer or solicitation would be contrary to the local laws and regulations of that jurisdiction, including, but not limited to persons residing in Australia, Canada, Hong Kong, Japan, Saudi Arabia, Singapore, UK, and the countries of the European Union.
The 2010s have been a boom era for online stock brokers. According to Statista, between 10% and 15% of all U.S. adults used an online broker at least once in 2018. While some major brokerages have remained the same (Charles Schwab), others have gone through mergers and acquisitions (E*TRADE acquired OptionsHouse; TD Ameritrade and Scottrade merged; TradeKing is now Ally Invest), and a new generation of millennial-focused brokers (like Robinhood and Acorns) has kept the old guard on its toes by lowering commission rates and minimum deposits. After digging into 25 trading platforms, here are the factors that set our top picks apart from the crowd.
Stock mutual funds or exchange-traded funds. These mutual funds let you purchase small pieces of many different stocks in a single transaction. Index funds and ETFs are a kind of mutual fund that track an index; for example, a Standard & Poor’s 500 fund replicates that index by buying the stock of the companies in it. When you invest in a fund, you also own small pieces of each of those companies. You can put several funds together to build a diversified portfolio. Note that stock mutual funds are also sometimes called equity mutual funds.