Introduction#

The brokerage industry has consolidated dramatically over the past decade. A handful of firms now manage the majority of retail investor assets, and commission-free trading has become the default. Understanding which are the top brokerage firms — and what actually makes them "top" — helps you evaluate where your money sits relative to the industry standard.

This guide covers the largest firms by assets, what criteria differentiate them, and how the business model shifted after the commission-free revolution.

The Largest Brokerage Firms by Assets#

As of late 2025 and early 2026, these are the dominant players by client assets:

Fidelity Investments — $18.0 trillion in assets under administration, $7.1 trillion in discretionary AUM, over 51 million retirement accounts. Fidelity's retail advisory solutions crossed $1.0 trillion AUM in Q3 2025.

Charles Schwab (including TD Ameritrade) — $11.90 trillion in client assets, 46.5 million total accounts (38.5 million active brokerage). Schwab completed the $1.3 trillion TD Ameritrade migration across 3.6 million RIA accounts. Revenue reached $23.9 billion in 2025, up 22% year over year.

Vanguard — $11.6 trillion in AUM as of September 2025, serving over 50 million clients. Vanguard remains the dominant force in index fund and ETF investing.

Interactive Brokers — 4.5 million client accounts (January 2026), $814 billion in client equity. IBKR added a record 1 million new accounts in 2025 and is the dominant choice for active and international traders.

Robinhood — 27 million funded customers, 28.4 million investment accounts, $324 billion in assets under custody. Record revenue of $4.5 billion in 2025, with Gold subscribers reaching 4.2 million.

*ETRADE* (now Morgan Stanley) — accounts are being migrated to the Morgan Stanley platform. ETRADE's brand continues for self-directed trading, with crypto trading via E*TRADE planned for early 2026.

International and forex-focused brokers#

  • IC Markets — 163,000 active trading accounts (Q2 2025), over $29 billion in daily FX volume, making it the largest retail forex broker globally by trading volume
  • Pepperstone — over 830,000 clients across 150 countries, AU$1 trillion in monthly trades
  • IG Group — 820,000 active clients (FY25), revenue above GBP 1 billion for the first time
  • Saxo Bank — 1.4 million clients (H1 2025), trades executed up 28% year over year

What Makes a Brokerage Firm "Top"#

Size alone does not determine quality. The factors that distinguish leading firms:

Regulation quality. Tier 1 regulators — FCA (UK), SEC/CFTC (US), ASIC (Australia) — impose strict capital requirements, mandatory fund segregation, regular audits, and compensation schemes. A broker regulated by the FCA with GBP 120,000 FSCS coverage offers fundamentally different protection than an offshore broker with no compensation scheme.

Client fund protection. In the US, SIPC covers up to $500,000 per account (including a $250,000 cash sub-limit) if a SIPC-member firm fails. Some brokers offer excess SIPC coverage — Fidelity, for example, has no per-customer limit on securities and a $1.9 million cash limit. In the UK, the FSCS increased coverage to GBP 120,000 per person per firm effective December 2025.

Market access. Interactive Brokers provides access to 150+ markets across 33 countries. CMC Markets offers 330+ forex pairs — the most in the industry. Breadth matters for traders who need international exposure or niche instruments.

Fee structure. Commission-free stock and ETF trading is now standard at all major US discount brokers. The differentiation has shifted to options pricing, margin rates, and the quality of order execution.

Technology and platforms. The platform determines your daily experience. Schwab's thinkorswim, IBKR's Trader Workstation, Saxo's SaxoTraderPRO, and IG's trading platform have all won independent awards for specific strengths.

The Commission-Free Revolution#

On October 1, 2019, Charles Schwab announced the elimination of commissions on US stock, ETF, and options trades — dropping from $4.95 to $0. Within days, TD Ameritrade matched (from $6.95 to $0), and its stock fell 25.8% in a single day. E*TRADE dropped 16.4%.

By 2026, every major US discount broker offers $0 commissions on US-listed stocks and ETFs. Options typically carry a per-contract fee of $0.50–$0.65.

How brokers earn revenue without commissions:

  • Payment for order flow (PFOF) — brokers route orders to market makers (Citadel Securities, Virtu Financial) who pay for the flow. Not all brokers accept PFOF — Interactive Brokers (pro accounts), Fidelity, and Vanguard do not.
  • Interest on uninvested cash — cash sweep programs earn the broker interest on client balances
  • Margin lending — interest charged on borrowed funds
  • Securities lending — lending out client shares to short sellers
  • Premium subscriptions — Robinhood Gold ($5/month, 4.2 million subscribers) is a significant revenue stream

Institutional vs Retail Brokers#

Retail brokers serve individual investors with user-friendly platforms, standard KYC processes, and smaller trade sizes. The focus is on accessibility and cost.

Institutional brokers serve banks, pension funds, hedge funds, and insurance companies. They provide access to dark pools and block trades, negotiate custom fee structures, process thousands of transactions per second, and must meet complex regulatory requirements. The platforms prioritise speed and depth over ease of use.

Some firms straddle both — Interactive Brokers serves retail clients through IBKR Lite while also operating one of the largest institutional brokerage operations globally.

Common Mistakes#

  1. Choosing solely on brand recognition. The biggest firm is not necessarily the best fit. A day trader needs fast execution and low margin rates. A long-term index investor needs low-cost ETFs and strong retirement account tools. Different priorities, different answers.
  1. Ignoring fund protection. SIPC covers securities up to $500,000, not the full account value if it exceeds that. FDIC does not directly insure brokerage accounts — it only applies to uninvested cash in certain bank sweep programs.
  1. Confusing AUM with safety. A firm managing trillions in assets is not inherently safer. Regulation, fund segregation, and compensation scheme coverage are what protect you if something goes wrong.

Key Takeaways#

  • The largest US brokerage firms — Fidelity, Schwab, and Vanguard — each manage over $11 trillion in client assets
  • Commission-free trading is now universal among major US discount brokers — differentiation has shifted to platform quality, margin rates, and order execution
  • SIPC covers up to $500,000 per account; FSCS (UK) covers up to GBP 120,000 — know what protection applies to your broker
  • For forex, IC Markets leads global retail volume at over $29 billion daily; IG Group, Pepperstone, and Saxo Bank are other major players
  • The right broker depends on what you trade, where you are located, and what features you prioritise — not just the name