Foundations5 min read

Account Types

The account a security is held in changes what can be done with it, how it is taxed and who has a claim on it. It is a structural decision, not an administrative one.

MadStockAlerts Research · Updated August 29, 2026

What to take away

  • The account type determines tax treatment, borrowing ability and withdrawal rules.
  • A taxable account is the most flexible and the only one taxed as it goes.
  • Retirement accounts trade flexibility for tax treatment, with withdrawal rules attached.
  • Joint and custodial accounts change who legally owns the assets, which is not reversible casually.
  • Cash and margin are a property of the account, not of any individual trade.

MAD Academy Training Video · 0:46

The Wrapper Decides the Tax

The same portfolio in a taxable account, an IRA and a Roth produces three completely different after-tax outcomes.

This lesson is part of a Stock Alerts + Tools plan.

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The families

TypeDistinguishing featureMain constraint
Individual taxableOne owner, no restrictions on withdrawalGains are taxed as they are realised
JointTwo or more ownersSurvivorship and ownership rules vary by form and by state
Traditional retirementContributions may be deductible; growth deferredWithdrawal rules and required distributions
Roth retirementContributions after tax; qualified growth untaxedIncome limits and contribution caps
CustodialHeld for a minor by an adultBecomes the child's property at the age of majority
Trust and entityHeld by a legal entityGoverned by the entity's own documents

The distinction that matters most for anything discussed elsewhere in this library is the first against the third and fourth. A taxable account produces a tax consequence every time a position is closed at a gain; a retirement account generally does not, which changes the arithmetic of frequency substantially.

Everything here describes how the account types work. It is not tax or legal advice, contribution and withdrawal rules change, and the treatment of any particular situation depends on circumstances only a professional can assess.

Two questions decide the account
Deferred or exemptTaxed as it happens
Restricted until an ageAvailable any time
Retirement accountsGrowth untaxed as it happens, and withdrawal rules with penalties attached
RareTax advantages generally come with strings. Some education and health accounts sit near here
Restricted taxableCustodial accounts: taxable, and the child's property at the age of majority
Individual and joint taxableFully flexible, and every realised gain is a taxable event
Access to the money
Tax treatment and access are the axes. Everything else about an account type follows from where it sits on them.

What the account type restricts

Beyond tax, the account form determines what strategies are permitted at all. Retirement accounts generally cannot be margined, which rules out short selling and most option structures requiring margin, because the account cannot pledge assets as collateral in the ordinary way.

  • Short selling requires borrowing shares, which requires a margin agreement.
  • Uncovered option selling requires margin, and brokers apply their own approval levels on top of the rules.
  • Some accounts restrict which securities may be held at all, particularly non-US listings and partnerships.
  • Withdrawal from a retirement account before the qualifying age generally triggers tax and a penalty, which makes the capital genuinely less available.

The last point is the one most often underweighted. Money in a retirement account is not a substitute for an emergency reserve, and a process that relies on being able to withdraw is relying on a withdrawal that carries a cost.

Custodial accounts and the age of majority

A custodial account holds assets for a minor, managed by an adult. The essential feature is that the assets belong to the child from the moment they are contributed: the custodian manages them and does not own them, and contributions are irrevocable gifts.

At the age of majority set by the relevant state, control passes to the beneficiary outright, with no conditions on what they do with it. That is a design feature rather than a defect, and it is the point that most frequently goes unconsidered when the account is opened.

Custodial assets also count as the child's assets for some financial aid calculations, which can affect eligibility more than the same assets held by a parent. The rules are specific and change; this is one of many places where a professional's view is worth more than a general description.

Beneficiaries, and why the form beats the will

Most account types allow a beneficiary to be named, and a valid designation generally passes the asset directly to that person outside the will and outside probate. That is efficient and it produces a specific failure mode.

  • A designation made years ago is the one that operates, whatever a later will says.
  • A divorce does not automatically remove a former spouse from every designation, and the rules vary.
  • A designation naming a person who has died, with no contingent named, can send the asset back through probate.
  • Employer plan accounts have their own rules, and spousal consent is required in some circumstances.

The first item is responsible for a recurring and entirely avoidable outcome: an estate carefully arranged by a will, undone by a form completed when an account was opened and never revisited.

The practical version is a review rather than a decision: every account, every designation, checked against what is currently intended. It takes an afternoon and it is one of the few things in this library with no trade-off attached.

Educational content only. MadStockAlerts provides market commentary, research, and educational content. It is not personalized investment advice, and nothing here is a recommendation to buy or sell any security. Trading and investing involve substantial risk, including loss of capital. See the Risk Disclosure and Customer Agreement.