You sell an investment and leave the proceeds in your trading app while you decide what to do next. The app charges no monthly fee. Your cash balance barely changes. But behind the screen, that money may be earning interest, with the company keeping part of it.
The cost to you can be interest you miss rather than a charge you see.
Free financial apps have several ways to earn revenue: holding cash, processing payments, selling upgrades, routing trades and lending securities. Understanding which ones your app uses helps you judge its value and spot the choices it benefits from encouraging. The examples below mainly concern U.S. services; products and rules vary by country.
Your cash can earn more than you receive
Many brokerages use a cash sweep: uninvested money is automatically moved into bank deposits or a money market fund. Other accounts leave it at the brokerage. These arrangements have different returns and protections, even when the app presents everything as one cash balance. The SEC explains the main cash arrangements.
In a bank sweep, the bank can pay the brokerage more than the brokerage passes on to you. The difference helps fund the service. The SEC notes that brokers commonly retain part of the interest as a sweep fee.
What a cash spread looks like
Hypothetical illustration, not current rates or a named provider’s offer. Assume a constant $10,000 balance for one year, simple annual interest, no compounding and no balance changes.
Where $400 of hypothetical annual interest goes
US dollars per year, hypothetical
- Customer receives: $100
- Brokerage retains before costs: $300
Of $400 paid into the hypothetical arrangement, the customer receives $100 and the brokerage retains $300 before costs.
| Where the money goes | Calculation | Annual amount |
|---|---|---|
| Bank pays into the sweep arrangement | $10,000 × 4% | $400 |
| Customer receives interest | $10,000 × 1% | $100 |
| Brokerage retains the difference | $400 − $100 | $300 |
That $300 is revenue available to cover costs, not $300 of operating profit. Real arrangements can involve other intermediaries and different terms.
It also isn’t automatically $300 you could have earned elsewhere. That depends on the alternatives actually available to you, including their fees, access restrictions and risks. The useful comparison is the return you receive after costs on genuinely comparable accounts.
Key takeaway 1
A zero account fee tells you little about what idle cash earns. Check the default cash option and its rate.
Your card spending generates fees
When you buy groceries with a card, the merchant pays to accept the payment. Part of the payment economics is interchange, a fee paid to the card issuer. A fintech providing the account may receive a share through its banking arrangements. The Federal Reserve explains debit-card interchange.
Chime describes interchange as its primary revenue source. Card use can therefore help fund an account without a monthly maintenance charge.
This does not mean a separate interchange charge appears on your bank statement each time you shop. It means someone else in the transaction pays a fee that helps support the service.
For the app, becoming your everyday spending account is valuable. For you, the sensible question is whether the account works well for spending you already intended to do. Making extra purchases to collect a small reward changes that calculation.
Free accounts can lead to paid products
A free tier can introduce customers to subscriptions, borrowing and optional services. Robinhood, for example, reports both Gold subscription revenue and net interest revenue in its financial results.
An upgrade may offer useful benefits. Compare its annual price with benefits you will actually use, and check whether attractive rates require a subscription, a qualifying deposit or a particular balance.
Other charges can appear only when you need something quickly. Chime’s own fee explanation identifies optional instant-transfer and out-of-network ATM fees, despite its lack of monthly maintenance fees.
Borrowing is another business. A brokerage may charge interest when you use a margin loan to buy investments. That loan can amplify losses as well as gains, so easy access should not be mistaken for suitability. The SEC explains margin’s risks.
A commission-free trade can still earn revenue
Some U.S. brokers receive payment for order flow, or PFOF. A trading firm pays the broker for sending it customer orders to execute. The customer may pay no brokerage commission on that trade.
The concern is the incentive: a broker choosing where to send your order also has a commercial relationship with the destination. U.S. brokers still owe best-execution duties; receiving PFOF does not remove those obligations or, by itself, prove a trade received a bad price. FINRA explains the requirements.
Rules differ across countries. Check the rules and disclosures for the company that actually holds your account, rather than assuming a U.S. example applies everywhere.
For a customer, the lesson is to look beyond the commission line. Execution quality includes the price received and how reliably an order is filled. A free trade is still a transaction whose terms matter.
Key takeaway 2
Follow who pays the app. Revenue from spending, trading or borrowing helps explain why those activities matter to its business.
Shares sitting in your account can be lent out
Some brokerages operate securities-lending programs. Shares are temporarily lent to a borrower for a fee, and participating customers may receive a share of the proceeds. Borrowers can use them for purposes including short selling and settling trades. The SEC describes how securities lending works.
Read the agreement before treating the income as an effortless bonus. Check consent, the revenue split and how to leave the program.
There are trade-offs. Robinhood’s U.S. disclosures, for example, say loaned shares lose voting rights while on loan, substitute dividend payments can have different tax treatment, and loaned securities are not covered by SIPC protection. The program uses collateral, but that does not eliminate every risk. Its lending terms explain the details.
A five-minute check of your own app
Start with your statement, fee schedule and account agreement:
- Cash: What rate am I receiving, where is the money held, and did I choose this option?
- Fees: Which withdrawals, transfers, conversions or upgrades cost extra?
- Trades: Does the broker receive routing payments, and where are its execution disclosures?
- Lending: Can my securities be lent, what do I receive, and what rights or protections change?
- Access and protection: Which legal company holds my money, how do withdrawals work, and what protection applies to this specific account?
That last question matters. In the U.S., FDIC insurance protects eligible bank deposits if an insured bank fails. It does not insure a nonbank app’s own failure. Coverage through an intermediary depends on conditions being met. The FDIC explains the distinction.
Key takeaway 3
A free app can offer good value. Judge the whole arrangement: what you earn, what you pay, how you access your money and what risks you accept.
Quick check
1. In the hypothetical table, what does the $300 represent?
A. Guaranteed operating profit.
B. The brokerage’s retained spread before costs.
C. Interest the customer has already received.
Show answer to question 1
Answer: B. The spread is revenue before operating costs and any other relevant expenses. It is not automatically profit.
2. Does payment for order flow automatically prove a U.S. customer received a bad trade price?
A. No.
B. Yes.
Show answer to question 2
Answer: A. It creates an incentive to examine. Actual execution quality and the broker’s duties still matter.
3. What can FDIC insurance protect when a nonbank app places eligible deposits at an insured bank?
A. Every investment made in the app.
B. The nonbank app against its own failure.
C. Eligible deposits against the insured bank’s failure, subject to coverage conditions.
Show answer to question 3
Answer: C. The bank and the app are separate businesses. The nonbank app itself is not FDIC-insured.
The next time an app says “free,” find its cash rate and fee schedule before deciding what that promise is worth.
This article explains business models, not personal investment advice. Features, fees and protections depend on the provider, product and jurisdiction.