Charles Schwab pioneered discount brokerage and now serves tens of millions of accounts with trading, advice and banking. The TD Ameritrade acquisition consolidated its position as the dominant US retail brokerage platform, alongside a major business serving independent financial advisors. Commissions are largely free; Schwab instead earns most of its money from the interest spread on client cash swept into its bank. Founded in 1971, the firm turned low-cost investing from a niche into the industry standard.