A cash brokerage account requires you to pay for investments in full. A margin account allows you to borrow from your broker, using eligible assets in the account as collateral. That borrowing can increase your purchasing power, but it also adds interest charges, repayment obligations and the risk of forced sales.
For New Mexico investors, the choice should start with how you intend to fund purchases, not which account displays the largest buying power figure. If you plan to buy stocks with money you already have, cash is the simpler starting point. Margin deserves a closer look only when you can explain why you need it and what happens if prices fall.
Cash vs Margin Accounts: The Practical Differences
| Feature | Cash account | Margin account |
|---|---|---|
| Funding purchases | You pay the full purchase price. | You can combine your money with a broker loan. |
| Borrowing interest | No margin interest because there is no margin loan. | Interest applies when you carry a margin loan. |
| After selling an investment | Settlement and payment rules govern reuse of proceeds. | Available buying power depends on credit, collateral and the broker’s requirements. |
| When prices fall | Your fully paid shares lose market value. | Your equity falls while the loan remains payable. |
| Main operational concern | Keeping purchases properly funded. | Monitoring debt, interest and required equity. |
Account type is only one part of choosing a brokerage. Compare the firm’s charges, service, investment access and account controls separately. Our guide to comparing online stock brokers for New Mexico residents covers that broader decision.
Do not treat “margin available” as a recommendation to borrow. It is a credit allowance, not extra savings. Your own spending limit can sit well below the number on the screen.
How a Cash Brokerage Account Works
In a cash account, you buy securities without taking a broker loan. The complication is timing: a completed trade and a settled trade are not the same thing.
Most U.S. stock and ETF trades settle one business day after the trade date, known as T+1. The standard settlement cycle shortened to T+1 on May 28, 2024. A Monday sale normally settles Tuesday; a Friday sale normally settles Monday, assuming no relevant holiday. The SEC’s T+1 settlement guidance sets out the rule and its exceptions.
Distinguish settled cash, money available to trade and money available to withdraw. These balances can differ. Before placing another order, check which balance the broker is displaying rather than relying on the account’s headline cash figure.
Unsettled Proceeds and Payment Violations
A cash account does not always require you to wait for sale proceeds to settle before making another purchase. A broker may permit a purchase using unsettled proceeds, but selling the replacement investment before its funding settles can create a payment violation.
Suppose you sell $2,000 of fully paid stock on Monday and use those unsettled proceeds to buy another stock that day. Selling the replacement stock on Monday, before the original sale settles, can trigger what brokers commonly call a good faith violation.
Freeriding is another payment problem: buying securities and using proceeds from selling those same securities to pay for the purchase. It can result in a 90-day restriction requiring purchases to be paid for in advance. The SEC’s bulletin on trading in cash accounts explains payment obligations and restrictions.
The safer operating habit is straightforward: identify the funds paying for each purchase and their settlement date. If you expect to sell the new position before that money settles, ask the broker whether the transaction would violate its cash account rules.
How a Margin Brokerage Account Works
A margin account gives the broker permission to extend credit against eligible account assets. Opening the account and actually borrowing are separate actions. Focus on your loan balance and transaction funding, not just the account label.
For ordinary purchases of eligible stocks, Federal Reserve Regulation T generally requires 50% initial margin. In a simple new purchase, that means contributing $5,000 toward $10,000 of stock and borrowing the other $5,000. This is not a promise that every investment qualifies or every account receives that buying power. The Federal Reserve’s Regulation T margin schedule sets the applicable initial requirements.
Separate three questions before borrowing: how much equity you need to begin, how much you must contribute to a purchase, and how much equity you must retain afterward. Those requirements serve different purposes.
Minimum Equity, Maintenance Requirements and Forced Sales
FINRA generally requires at least $2,000 in account equity before margin borrowing. For ordinary long margin stocks, the maintenance minimum is generally 25% of current market value. Brokers can impose higher “house” requirements and raise them without advance written notice.
If your account falls short, the broker can require more collateral or sell assets. It need not issue a margin call before selling, and you do not have the right to choose which holdings it sells. These risks are covered in FINRA’s guidance on margin calls and liquidation.
That makes the maintenance percentage a boundary, not a sensible target. Leaving almost no cushion means a relatively small price move or a higher house requirement can disrupt your plan.
A Worked Example: The Same Savings, Different Exposure
Consider two hypothetical investors, each starting with $10,000. One buys $10,000 of stock in a cash account. The other contributes $10,000 and borrows another $10,000, buying $20,000 of the same stock.
If the stock rises 20%, the cash investor owns shares worth $12,000, a $2,000 gain. The margin investor owns shares worth $24,000. After subtracting the $10,000 loan, their equity is $14,000, a $4,000 gain before interest and other charges.
Now reverse the price move. A 20% decline leaves the cash investor with $8,000, a $2,000 loss. The margin investor’s holdings fall to $16,000, but the loan remains $10,000. Their equity falls to $6,000: a $4,000 loss, or 40% of their original savings.
The stock moved by the same percentage in both accounts. Borrowing changed the exposure relative to the investor’s own money.
How a Maintenance Shortfall Develops
Continue the margin example and assume the broker applies a hypothetical 30% maintenance requirement. If the holdings fall to $14,000, subtracting the $10,000 loan leaves $4,000 of equity.
Required equity would be $4,200: 30% of $14,000. The account is therefore $200 short. A $200 cash deposit would close that simplified shortfall, assuming no further price changes, interest charges or other positions.
The calculation is:
Account equity = market value of holdings minus the margin loan.
These examples exclude fees and interest and assume the positions remain open. Actual liquidation can occur before an investor reaches the illustrated balance. A sharp price gap can also leave sale proceeds insufficient to repay the debt.
Margin Interest Changes the Break-Even Point
A profitable stock position does not necessarily produce a profitable borrowing decision. Interest consumes part of the return, and the loan still costs money when the investment goes nowhere.
At a hypothetical annual interest rate of 10%, a constant $10,000 loan costs about $1,000 over a year before compounding or other charges. If the $20,000 stock position in the earlier example stays flat, that financing cost still reduces the investor’s equity.
The rate is illustrative, not a current broker quote. Check the rate for your expected loan balance, whether it can change, how interest accrues and when charges are added. The SEC’s margin account bulletin covers borrowing costs, agreements and the possibility of losses exceeding your investment.
For a proposed trade, write down the dollar cost of borrowing alongside the hoped-for gain. “The stock should rise” is not much of a financing plan. The return must justify both the expense and the added risk.
Day Trading Rules Are Changing: Check Your Broker’s Transition
As of October 19, 2026, investors should not assume every broker applies the same day trading framework. FINRA’s new intraday margin standards became effective June 4, 2026, but firms have a transition period through October 20, 2027.
The new standards replace the previous pattern day trader framework, including its trade-count designation and $25,000 minimum equity requirement. During the transition, a firm may still operate under the old requirements. FINRA Regulatory Notice 26-10 establishes the dates and replacement framework.
Before trading frequently, ask your broker which system governs your account, how it calculates intraday requirements and what happens after a deficit. Do not rely on an old article saying the $25,000 rule applies everywhere, or a newer headline saying it has disappeared from every account.
A cash account is not an unrestricted substitute. Its payment and settlement obligations still matter, especially when repeatedly recycling the same funds. Keep the account choice separate from the decision to trade frequently; our guide to day trading costs, rules and risks for New Mexico residents addresses that wider issue.
Which Account Fits Your Intended Use?
A cash account is generally the cleaner choice when you intend to buy fully paid shares, add money periodically and avoid financing costs. It removes the temptation to turn a $5,000 investing budget into a much larger market position.
It does not make the investments safe. A poorly chosen stock can still lose most or all of its value. What cash removes is the broker loan attached to that purchase, not the stock’s business or market risk.
Margin may warrant consideration when you have a defined need for credit or a strategy requiring a margin account. The justification should be more substantial than impatience with settlement or a desire to recover losses faster.
Test the decision against an uncomfortable scenario: your holdings fall sharply, the broker raises its requirement, and your next paycheck has not arrived. Could you reduce the position or provide funds without using rent money, emergency savings or another expensive loan? If the answer depends on prices recovering promptly, the borrowing plan is fragile.
What to Check Before Opening or Switching Accounts
Read the account selection screen and agreement rather than accepting the default. Ask the broker to confirm these points in writing:
- Account permissions: Are you opening a cash account or authorizing margin credit?
- Funding controls: Which displayed balance can you use without creating a loan or payment violation?
- Borrowing terms: What interest rate, collateral requirements and liquidation rights apply?
- Trading restrictions: Which cash payment rules or intraday margin framework governs your account?
If you want to remove margin, ask what must happen to existing debt, open orders and positions first. Do not assume changing a setting erases an obligation.
Save agreements, trade confirmations, statements and interest records. Our guide to trading records for New Mexico investors covers organizing that paperwork without turning this account comparison into a tax guide.
Choose the account that supports your intended purchases with the fewest unnecessary obligations. For fully funded investing, cash is usually enough. Borrow only when the purpose, cost and repayment risk are clear before the order goes through.