Every Time You Trade, Borrow or Sit in Cash, Someone Else Gets Paid
Retail investors don't just lose to bad information. Much of the financial industry earns more from trading, borrowing, cash balances and attention than from investor returns themselves.
The market earns more easily from your activity than from your returns
It takes time for a company to grow earnings, build cash flow, and let shareholders collect the fruits of compounding. Financial infrastructure works differently. It can generate revenue the moment an order hits the market, today. A $0 trading commission does not mean the economic cost is zero. Revenue comes in layers: the spread and price improvement embedded in order execution, options trading revenue, what the firm earns on customer cash, advisory fees, and interest on margin loans.
None of this makes the structure inherently unfair. Brokers and market makers provide liquidity, execution, custody and credit. The problem is that the behavior that maximizes a firm's revenue does not always match the behavior that maximizes an individual's long-term compounding.
Even in the age of "free trading," an order is never free
Payment for order flow, or PFOF, is the practice where a broker routes customer orders to a specific market maker in exchange for payment. Describing this simply as "selling retail order data" is inaccurate. The SEC has stated that PFOF, cash sweep programs, and various fees and sales incentives can create conflicts of interest. At the same time, brokers carry a best-execution obligation.
The important question isn't whether a broker is cheating you. The more useful question is how much invisible, compounding cost builds up as you trade more often, and how much that erodes your investment results. In the classic study by Barber and Odean, among 66,465 households, the group that traded most actively earned an annualized return of 11.4%, well below the 17.9% market return over the same period. The sample and the era are dated, but the finding remains a leading piece of evidence on the cost of overtrading.
11.4% — annualized return of the most active-trading households 17.9% — market return over the same study period 75% — average annual portfolio turnover for the typical household
The real danger of trading on margin isn't the loss percentage, it's losing time
The math of margin is simple. Put up $100,000 of your own capital, borrow another $100,000, and invest $200,000 total. If the stock drops 30%, the position falls to $140,000. The $100,000 loan is unchanged, so your equity falls to $40,000, a 60% decline. Interest and trading costs come on top of that.
The bigger issue is path dependency. A cash investor can sit through a 30% drawdown and wait for a recovery. A margin investor who breaches a maintenance requirement doesn't get that option. The SEC notes that a broker can sell securities to meet a margin shortfall without consulting the customer first, and can raise maintenance margin requirements without advance notice.
Borrow $100,000 at 8% annual interest and you owe $8,000 a year just in interest. If the stock goes sideways, the asset price hasn't moved, but the investor's break-even point keeps drifting further away. The biggest cost of leverage sits on the opposite side of "amplified returns": the possibility of forced liquidation.
Broker earnings make the structure clearer
Charles Schwab, one of the largest US brokerages, reported net revenue of $23.921 billion in 2025. Net interest revenue made up $11.750 billion of that, roughly 49% of the total. Trading revenue came to $3.921 billion, of which $1.930 billion was tied to order flow. Schwab discloses that the asset base behind its net interest revenue includes customer cash, margin loans, bank loans and bonds.
| Schwab 2025 | Amount | Share of net revenue |
|---|---|---|
| Total net revenue | $23.921B | 100% |
| Net interest revenue | $11.750B | ~49% |
| Trading revenue | $3.921B | ~16% |
| Order flow revenue | $1.930B | ~8% |
These numbers don't mean a broker profits from customer losses. They point to something more important: brokers have a structure that can generate recurring revenue from the customer relationship, independent of whether the customer's market bets pay off. What an individual investor needs is not to treat this structure as an enemy, but to control the unnecessary costs within their own reach.
Media needs a new story every day. A portfolio does not need to change every day
Financial media and investment content carry their own structural tension. Advertising and subscription businesses depend on sustained attention. Since markets move every day, there's always a new interpretation to produce. But a company's long-term cash flow and competitive position usually doesn't change on a daily basis.
That argues for changing how you use news. Don't treat a headline as a trading signal. Treat it as a tool for testing your investment thesis. Better questions to ask first: Will this still matter in three years? Does it actually damage the company's long-term cash flow? Is this new fact one that breaks my original investment case?
The advantage of dollar-cost averaging isn't the highest return, it's turning behavior into a system
Dollar-cost averaging is not a strategy that guarantees higher returns than investing a lump sum all at once. If markets trend upward over the long run, there are plenty of stretches where deploying cash you already have, quickly, works out better. DCA's real strength lies elsewhere: it's a behavioral rule that lets you invest a recurring cash flow, like a paycheck, on a regular schedule, without letting fear or greed dictate the timing of each purchase.
For long-term investors, three things matter more than the doctrinal fight over DCA versus lump sum: avoiding leverage you cannot handle, keeping turnover low, and building a capital structure that lets you stay in the market as long as your investment thesis remains intact.
