What it means
Private investors cannot deal directly on an exchange, so a broker provides the access and then handles settlement, custody and reporting. The broker acts as an agent on instruction, which is a different job from an investment manager who decides what to buy.
The industry splits roughly into execution-only brokers, which simply carry out your instructions cheaply, and advisory or full-service brokers, which add research and recommendations for a higher charge. Discretionary managers go a step further and trade without asking each time, usually for a percentage fee on the assets they look after.
Charging models are where the real differences show up. Execution-only platforms typically quote a flat fee per trade plus a small annual custody charge, while full-service brokers have historically charged a percentage of each trade's value.
For a business, brokers matter well beyond personal investing. Corporate finance teams use them to place new share issues, to run buy-back programmes and to manage treasury holdings, and employee share plans are usually administered through a broker.
Anyone choosing a broker should look past the headline commission at custody fees, foreign exchange charges, interest paid on cash balances and how client assets are protected if the firm fails. Those items frequently cost more over a year than the trading commission ever does.
In practice
Real-world examples.
Example
A retired teacher moves a $180,000 portfolio from a full-service broker charging 0.75% a trade to a flat-fee platform charging $9.00. Making about 12 trades a year, the annual cost falls from roughly $1,620 on $18,000 of average trade value per deal to $108.
Example
A mid-sized engineering group runs a $4,000,000 share buy-back and appoints a broker to purchase shares in the market on its behalf under strict daily volume limits. The broker's role is purely execution, but the compliance rules around timing and disclosure are the reason the company will not do it directly.
Example
A technology company administers its employee share scheme through a broker, which holds the shares in a nominee account, sells enough on vesting to cover tax, and reports the proceeds to payroll. Employees see a single statement rather than dealing with an exchange themselves.
Formula
Calculation
Commission = Trade Value x Commission Rate, or a flat fee per trade
Total Cost of Purchase = Trade Value + Commission
An investor buys 500 shares at $60.00 each, so the trade value is 500 x $60.00 = $30,000.
A full-service broker charging 0.4% takes 0.4% x $30,000 = $120. The total outlay is $30,000 + $120 = $30,120, an effective price of $30,120 / 500 = $60.24 a share.
An execution-only broker charging a flat $10.00 brings the total to $30,000 + $10.00 = $30,010, or $30,010 / 500 = $60.02 a share. The saving on this single trade is $120 - $10.00 = $110, and for an investor placing 20 trades a year the difference is 20 x $110 = $2,200.
If the same investor instead used a discretionary manager charging 1% a year on a $500,000 portfolio, the annual fee would be 1% x $500,000 = $5,000. That only makes sense if the advice and administration are worth more than $5,000 a year, which is a far bigger question than the price of any individual trade.Case study
Seen in the real world.
The following is an illustrative and entirely fictional example. Pemberly Wealth, an invented brokerage, offered a headline rate of $4.95 a trade and won a large number of accounts from a rival charging $12.00.
One customer of this fictional firm moved a $250,000 portfolio across on the strength of that headline. In the first year she placed 30 trades, saving 30 x ($12.00 - $4.95) = $211.50 on commission. What she had not read was the 0.45% annual custody charge, which came to 0.45% x $250,000 = $1,125, against her previous broker's flat $180 a year.
She also held two overseas holdings, and Pemberly's 1.5% foreign exchange margin on dividends cost roughly another $90 across the year. Her total cost rose by about $211.50 saved against $945 of extra custody and $90 of currency charges, leaving her around $824 worse off. She moved back, and the episode is a reminder that with brokers the headline commission is rarely the number that decides the outcome.
Watch out
Common mistakes.
- Choosing a broker on headline commission alone and overlooking custody fees, currency margins and inactivity charges that can cost far more each year.
- Assuming a broker is giving advice, when an execution-only service is contractually limited to carrying out instructions and offers no recommendation at all.
- Ignoring how client assets are held and protected, which matters enormously if the broker itself gets into financial difficulty.
Questions
People also ask.
What is the difference between a stockbroker and a financial adviser?
A stockbroker executes securities transactions and may recommend specific trades, while a financial adviser looks at the whole financial picture including tax, pensions and protection.
Do I need a stockbroker to buy shares?
In practice yes, because exchange access is restricted to members, although modern online platforms are brokers offering that access at very low cost.
How are brokers paid if they advertise zero commission?
Usually through the spread between buying and selling prices, interest earned on client cash balances, currency conversion margins or payment for routing orders to particular venues.
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