Cash Account vs Margin Account: T+1 Settlement, Good Faith Violations, Margin Calls, and Which One an Automated Trader Should Use

A cash account lets you buy securities only with money you have already deposited and that has settled. A margin account lets your broker lend you money against the securities you hold, so you can buy more than your cash, sell short, and reuse the proceeds of a sale immediately. The cash account's cost is patience: proceeds from a sale are not yours to spend again until the trade settles, one business day later. The margin account's cost is interest on what you borrow and the possibility of a margin call. For most people trading their own rules, including with automation, the choice comes down to one question: do you need to redeploy money the same day, or can you wait until tomorrow?

This guide explains settlement under the T+1 rule, the two cash-account violations that get accounts restricted for 90 days, how margin works and what a margin call actually does, what changed when the pattern day trader rule ended in June 2026, and what the brokers we connect to actually report as spendable money, which is not the same number at every broker. It ends with which account type suits an automated trader and why.

Settlement: why your money is not yours again until tomorrow

When you sell a stock, the trade is agreed instantly but the money and the shares change hands on the settlement date. Since May 28, 2024, settlement for U.S. stocks, ETFs and most bonds is T+1: the next business day after the trade, per the SEC's investor bulletin on the change. Business days exclude weekends and market holidays, so the calendar matters:

• Sell on Friday, October 16, 2026: settles Monday, October 19.
• Sell on Wednesday, November 25, 2026: the market is closed Thursday for Thanksgiving, so it settles Friday, November 27.
• Buy on Thursday, December 24, 2026: Christmas Day is a holiday and then the weekend, so payment is due Monday, December 28.

In a margin account none of this slows you down, because the broker extends you credit against the pending proceeds. In a cash account it is the whole game. You may place a buy order with unsettled proceeds at most brokers, but what you do next is where the violations live.

The two cash-account violations

Good faith violation. You sell stock A on Monday, use the unsettled proceeds to buy stock B the same day, then sell stock B on Monday too, before Monday's sale of A has settled on Tuesday. You sold B before you had paid for it with settled money. FINRA's description is exactly that: buying with cash from a transaction that has not settled, then selling before those proceeds settle. Brokers typically allow a small number of these in a rolling twelve months, often three, before restricting the account to settled cash only for 90 days. The fix is simple: anything bought with unsettled proceeds must be held until those proceeds settle, which under T+1 means until the next business day.

Free-riding. You buy a stock with no cash in the account, sell it, and use the proceeds of that sale to pay for the purchase. The money never came from you. This one is written into the Federal Reserve's Regulation T, which withdraws "the privilege of delaying payment beyond the trade date" for 90 calendar days: during the freeze you can still trade, but every purchase must be paid for with cash already in the account before the order is placed.

Neither violation applies in a margin account, because the broker's credit covers the gap. That is the honest reason many active traders switch to margin even if they never intend to borrow a dollar overnight.

How a margin account works, and what a margin call is

Under Regulation T you can borrow up to 50% of the purchase price of most stocks, so $10,000 of cash supports $20,000 of stock. FINRA then requires you to keep at least 25% equity in the account, and most brokers set their own house minimum higher, often 30% or more, per the SEC's margin bulletin. Equity is the value of the securities minus the loan. If the stock falls far enough that your equity drops below the maintenance level, the broker issues a margin call: deposit cash or securities, or sell positions, and if you do not act quickly the broker can sell for you, in whatever order it chooses, without calling first. The bulletin is explicit that the broker can do this without your consent.

Worked example. You buy $20,000 of stock with $10,000 of your cash and a $10,000 loan. The stock falls 30% to $14,000. Your equity is now $4,000, which is 28.6% of the position: above the 25% federal minimum, below a 30% house minimum, so a house call arrives. At a 35% fall, equity is $3,000 on $13,000, or 23%, and the call is federal. A 30% drop in a stock you own outright costs you 30%. The same drop on 50% margin costs you 60% of your own money, plus interest on the loan the whole time.

Margin interest is charged daily on the borrowed balance and varies by broker and balance; it is the one trading cost that compounds while you wait. If you hold leveraged positions for weeks, it is usually larger than commissions and slippage combined.

What the end of the PDT rule changed

Until June 4, 2026, a margin account that made four or more day trades in five business days with under $25,000 of equity was flagged a pattern day trader and restricted. That rule is gone; our guide to the change covers the replacement intraday margin standard. Two consequences for the cash-versus-margin decision:

• Small margin accounts can day trade again. The reason many sub-$25,000 traders used cash accounts, to escape the PDT label, no longer exists. A margin account now gives a small account immediate reuse of proceeds without the old trigger.
• Cash accounts were never limited by PDT, and still are not. The limit in a cash account is settled money, not a rule. You can make as many same-day round trips as your settled cash allows; the constraint is that each dollar can be used once per settlement cycle.

What brokers actually report as spendable: notes from our integrations

JorgAI's auto-trader sizes every order from the broker's own spendable figure, by default 80% of what the broker reports, and 82 of the 83 accounts in our settings table size from cash rather than a fixed share count. Integrating four brokers taught us that "spendable" is not one number:

• Alpaca reports buying power, cash, and a separate settled-cash figure, and labels the account cash or margin through a multiplier field (1 for cash, 2 or 4 for margin). The trap we hit in production: Alpaca's instant funding makes stock buying power positive the moment a deposit is initiated, but crypto orders draw only on settled cash, so a freshly funded account can buy stock and have its crypto orders rejected until the deposit settles. If you automate an Alpaca account and crypto, fund it a day early.
• Charles Schwab reports a buying-power figure for margin accounts and cash available for trading for cash accounts, plus a margin balance that is the current loan. The account type comes back as a plain label, and in a cash account the spendable number already excludes unsettled proceeds, so the broker's figure does the settlement math for you. Automating a Schwab account is the most common setup among our members.
• tastytrade returns a margin-or-cash flag on the account record and an equity buying power figure, with a negative cash balance representing the margin loan.

The practical consequence: an automated system that reads the broker's spendable figure inherits the account type's rules automatically. In a cash account it will simply have less to spend the morning after a busy day, because yesterday's proceeds have not settled. In a margin account it will have the full amount, and the loan, if any, is visible as a negative cash balance. Our own members' live automated trades close quickly, a median of 36 minutes from entry to exit, so in a cash account the proceeds of a morning trade are typically unavailable until the next session while a margin account would redeploy them at once.

Which account should an automated trader use?

• Cash account if you want a hard ceiling on losses equal to the money you deposited, you hold positions for a day or more, and you do not mind that each dollar works once per day. It is also the only choice for an IRA. Pair it with a daily spend limit and the settlement cycle takes care of the rest.
• Margin account with no borrowing if you make several round trips a day and need the proceeds back immediately. Keep the broker's leverage off by capping total exposure at or below your cash, so you get same-day reuse of proceeds and short-selling access without ever paying interest or risking a call. This is the configuration most active traders actually want and the one we recommend when asked about safety.
• Margin account with borrowing only if you understand that losses are magnified by the loan, interest accrues daily, and the broker can liquidate without asking. An automated system makes this more dangerous, not less, because it will use the buying power it is given. If you run one on margin, set its exposure cap in dollars, not as a percentage of buying power.

Whichever you choose, the controls that matter, a daily spend limit, a total exposure cap, a stop on every position and a daily loss brake, work the same way in both. If you would rather have them enforced for you inside the brokerage account you already have, that is what JorgAI does. Set them once and the account type handles the settlement arithmetic.

Quick answers

What is the difference between a cash account and a margin account? In a cash account you buy only with settled money you have deposited. In a margin account the broker lends you money against your securities, which allows leverage, short selling, and immediate reuse of sale proceeds, at the cost of interest and margin-call risk.

Can you day trade in a cash account? Yes. The pattern day trader rule never applied to cash accounts and it ended for margin accounts on June 4, 2026. The limit in a cash account is settled cash: each dollar can be used once per settlement cycle, which under T+1 is one business day.

What is a good faith violation? Buying a security with the unsettled proceeds of a sale and then selling it before those proceeds settle. Brokers usually allow a few per year before restricting the account to settled cash for 90 days.

How long does it take for stock sales to settle? One business day after the trade date (T+1) since May 28, 2024, for U.S. stocks and ETFs. Weekends and market holidays do not count, so a Friday sale settles Monday.

What happens if I get a margin call? You must bring equity back above the maintenance level by depositing cash or securities or selling positions. If you do not act in time, the broker can sell positions of its choosing without your consent.

Is a margin account safe if I never borrow? A margin account with exposure capped at or below your cash behaves like a cash account with same-day reuse of proceeds. The risk only appears when positions exceed cash and a loan exists. Set the cap in dollars so an automated system cannot drift above it.

Sources: SEC Office of Investor Education bulletins on the T+1 settlement cycle and on margin accounts; FINRA, "Frequent intraday trading" (June 4, 2026); 12 CFR 220.8 (Regulation T, cash accounts). Settlement examples use the 2026 NYSE holiday calendar. Broker behavior described is what JorgAI's integrations observe through each broker's API as of October 2026 and may change. Account-settings and hold-time figures are from JorgAI members' accounts through October 12, 2026 and describe configuration and mechanics, not returns. This article is education, not investment advice.