In terms of volume, Interactive Brokers is technically the largest online stock trading platform in the U.S. It also advertises itself as the “lowest cost broker,” and for good reason: It only charges a startlingly low $0.005 per trade on stocks, ETFs, options, bonds, mutual funds, and futures (plus a 7 cent per contract fee for options). Technically, that’s still higher than Robinhood, but Robinhood only offers stocks, ETFs, and options (and as we noted above, Robinhood does skim some money off the top of trades via “payment for order flow”).
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.
When it comes to research, Fidelity is in a league of its own. The intellectually curious can dive into research from more than 20 providers, including Recognia, Ned Davis, and McLean Capital Management. Fidelity’s Learning Center featured videos are organized by topic, but they don’t stop after explaining the concept; they also cover how to apply principles to your own Fidelity investments.
Different investors are going to prioritize different things. A day trader, for example, requires speed and flexibility. A first-time trader may value educational resources and reliable customer support. But one thing every trader should care about is cost. Not paying attention to investment expenses is like revving your car engine while filling it with gas. That's why we spent a lot of time balancing price with what each site offered.
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.