For the active trader, execution speed and fill price are very important. I won’t get too in depth here but I have tested many of these brokers and there can be noticeable differences in trade execution times and quality. For the majority of investors, saving a penny per share on a 100 shares order isn’t the end of the world, but for active traders it is something to look into. To understand Order Execution, read this guide.
Why I’m buying: Spell out what you find attractive about the company and the opportunity you see for the future. What are your expectations? What metrics matter most and what milestones will you use to judge the company’s progress? Catalog the potential pitfalls and mark which ones would be game-changers and which would be signs of a temporary setback.

A broker is simply a licensed person through whom you can buy and sell these stocks. When you use an online platform, it essentially acts as an online broker. If someone wants to buy any product, he can contact a brokerage service. They would place an order and let him know the market price of the product. If the investor is interested, they would include a commission for themselves and process the order forward. If the user wishes to buy stock, the broker would forward his order to a stock exchange, which would approximately take 3 days to complete including the money exchange between the broker and the investor.