NerdWallet's ratings for brokers and robo-advisors are weighted averages of several categories, including investment selection, customer support, account fees, account minimum, trading costs and more. Our survey of brokers and robo-advisors includes the largest U.S. providers by assets under management, plus notable and/or emerging players in the industry. Factors we consider, depending on the category, include advisory fees, branch access, user-facing technology, customer service and mobile features. The stars represent ratings from poor (one star) to excellent (five stars). Ratings are rounded to the nearest half-star. Is Stock Trading Easy?
According to one interpretation of the efficient-market hypothesis (EMH), only changes in fundamental factors, such as the outlook for margins, profits or dividends, ought to affect share prices beyond the short term, where random 'noise' in the system may prevail. The 'hard' efficient-market hypothesis does not explain the cause of events such as the crash in 1987, when the Dow Jones Industrial Average plummeted 22.6 percent—the largest-ever one-day fall in the United States.