Short answer: choose a margin broker only after matching the legal entity, account regime, borrowing currency, rate formula, house requirements and liquidation process to a controlled use case. The lowest displayed rate is not enough and leverage can create losses beyond deposited cash.
Define the account product and legal entity
A securities margin loan, US portfolio margin, option or short-sale permission and CFD collateral are different arrangements. Identify the account entity and agreement before comparing numbers. This global guide uses US rules only where labelled and is educational rather than personal advice. See Margin and Options Permissions Explained.
Regulatory minimums and house rules
| Layer | What it can set | Check |
|---|---|---|
| Law and regulator | Baseline eligibility disclosure and minimum requirements in that jurisdiction. | Entity regulator and account agreement. |
| Venue or clearing | Product and market requirements. | Exact instrument and position. |
| Broker house rule | Higher maintenance concentration and risk add-ons. | Live requirement and disclosure. |
| Intraday risk system | Buying power alerts restrictions and liquidation. | Platform preview and stress test. |
Calculate total borrowing cost
Record the settled debit, currency, benchmark, broker spread, tier method, day-count basis and accrual timing. Add subscription, market data, conversion and stock-borrow cost only when separately applicable. Rates can change without notice, so save the dated official page and calculate cost for the expected balance and holding period.
Liquidation and account shortfall
A broker can increase house requirements and sell positions without waiting for the customer under applicable agreements. A fast price move or concentrated holding can create a debit even after liquidation. Decide which assets may be sold, whether notices are informational rather than promises and how a shortfall must be funded.
Currency borrowing
Buying a foreign security can create a loan in its settlement currency instead of an immediate conversion. Compare the borrowing rate and FX path separately, then inspect every cash balance after the trade. Base currency may be a reporting setting rather than an instruction to convert.
Eligibility concentration and portfolio margin
Eligibility depends on residence, entity, experience, account equity and product permissions. Portfolio margin is a distinct risk-based regime and is not a synonym for a normal margin account. Brokers can raise requirements for volatility, liquidity, concentration, short positions or hard-to-borrow securities.
Risk tools and alerts
Useful controls show settled cash, debit by currency, initial and maintenance excess, stress loss and the position driving a requirement. Test alerts before borrowing, but do not rely on an alert as a guaranteed grace period. Define a lower internal limit than the broker liquidation threshold.
Dated broker evidence
| Scope | Published method | Boundary |
|---|---|---|
| Interactive Brokers public schedule | Rates are published by currency debit tier and benchmark spread; requirements and account configuration are separate pages. | Entity plan currency tier product and live benchmark must be rechecked. |
| Robinhood Financial US | Support publishes variable balance tiers and daily interest on settled margin balances. | US eligibility subscription terms and current formula apply; rates may change. |
| Webull Financial US | Support describes daily accrual from average daily debit and separate short-stock borrow charges. | Account requirements plan rate settlement timing and hard-to-borrow cost must be checked. |
Best fit by scenario
| Scenario | Priority | Stop condition |
|---|---|---|
| Short controlled bridge | Known debit duration rate and liquid collateral. | No cash repayment plan. |
| Multi-currency portfolio | Debit by currency FX control and statements. | Unexplained negative cash. |
| Active hedged account | Live requirements stress tools and execution. | Options or shorts used without separate permission analysis. |
| Long-term unleveraged investing | Cash account and clear settlement. | Margin adds no defined benefit. |
Red flags
- A CFD collateral percentage is compared with a securities-loan interest rate.
- A US regulatory minimum is promised across every country and entity.
- The page quotes a rate without date currency debit tier and formula.
- Buying power is shown without maintenance or liquidation risk.
- A broker alert is treated as a guaranteed cure period.
- Margin is used to recover losses or fund an open-ended cash need.
Decision workflow
- Write the purpose maximum debit currency and deadline.
- Confirm legal entity account regime and product permission.
- Capture the current rate formula and calculate one holding period.
- Check maintenance concentration and house add-ons.
- Read liquidation and deficit provisions.
- Test cash balances alerts and stress views without a large position.
- Set an internal limit and cash repayment plan.
FAQ
Can the broker liquidate without contacting me?
It can under many margin agreements. Regulatory education warns that firms may sell securities without consulting the customer. Read the exact entity agreement.
Is portfolio margin simply a cheaper margin account?
No. It is a distinct risk-based regime with eligibility and model-driven requirements that can change with the portfolio.
Should I compare only the annual rate?
No. Match currency, debit tier, benchmark, spread, accrual, subscription, FX and holding time.
Does investor protection repay a margin loss?
No. Compensation schemes do not insure market losses or a lawful debit created by borrowing.
Sources and methodology
We separate account regime, rule hierarchy, borrowing formula, liquidation and controls. Broker examples are dated to the named US or public schedule and are not global recommendations.
- Investor.gov: Understanding Margin Accounts
- FINRA: Margin Calls
- FINRA: Margin Disclosure Statement
- Interactive Brokers: Margin Rates
- Interactive Brokers: Margin Requirements
- Interactive Brokers: Account Configuration
- Robinhood US: Margin Rates
- Robinhood US: Margin Investing
- Webull US: Interest and Short Selling Fees
- Webull US: Margin Account Requirements
Last checked and update policy
Last checked: 15 July 2026. Recheck immediately after a rate formula, benchmark, account eligibility, requirement, liquidation or product-permission change.
Next step
Build one dated borrowing worksheet and one liquidation stress case before enabling margin. Continue with Broker Fees Explained.