Glossary: Taxes and Regulations Terms

Navigating investment taxation requires fluency in a specialized vocabulary that spans the Internal Revenue Code, SEC regulations, and brokerage reporting standards. This glossary defines the essential terms investors encounter when managing the tax implications of their portfolios.

Capital Gains and Losses

Capital Gain

The profit realized when a capital asset (stock, bond, real estate, cryptocurrency) is sold for more than its cost basis. Capital gains are classified as short-term or long-term based on holding period.

Capital Loss

The loss realized when a capital asset is sold for less than its cost basis. Capital losses offset capital gains dollar-for-dollar, with up to $3,000 of excess losses deductible against ordinary income per year.

Short-Term Capital Gain

Gain on an asset held for one year or less. Taxed at ordinary income tax rates (10%-37% for 2025).

Long-Term Capital Gain

Gain on an asset held for more than one year. Taxed at preferential rates of 0%, 15%, or 20% depending on taxable income.

Cost Basis

The original purchase price of an asset plus any acquisition costs (commissions, fees). Used to calculate gain or loss upon sale.

Adjusted Basis

Cost basis modified by subsequent events — stock splits, return of capital distributions, premium amortization, OID accrual, or other adjustments.

Stepped-Up Basis

When an asset is inherited, the heir's basis is reset to the fair market value on the date of the decedent's death, eliminating unrealized gains that accrued during the decedent's lifetime.

Carryover Basis

When an asset is received as a gift, the recipient takes the donor's original cost basis, preserving any built-in gain.

Netting Rules

The IRS process of offsetting gains and losses: short-term gains and losses net against each other first, long-term gains and losses net against each other, then the two net results offset each other.

Tax-Lot Management

Tax Lot

A record of a specific purchase of securities, including the date, number of shares, and price per share. Each purchase creates a separate lot.

FIFO (First-In, First-Out)

The default cost basis method where the oldest shares purchased are deemed sold first.

LIFO (Last-In, First-Out)

A cost basis method where the most recently purchased shares are deemed sold first. For securities, this is implemented through specific identification.

Specific Identification

A cost basis method allowing the investor to select exactly which tax lots to sell, providing maximum control over gain/loss recognition and holding period character.

Average Cost Method

A cost basis method available only for mutual fund shares, where total cost is divided by total shares to produce a single average per-share basis.

Withholding and Estimated Taxes

Estimated Tax Payments

Quarterly payments required when tax owed exceeds withholding by $1,000 or more. Due April 15, June 15, September 15, and January 15.

Safe Harbor

A threshold that, if met, guarantees no underpayment penalty — either 100% of prior year tax (110% if AGI > $150,000) or 90% of current year tax.

Underpayment Penalty

Interest charged by the IRS on estimated tax payments that were insufficient or late. Calculated at the federal short-term rate plus 3 percentage points.

Backup Withholding

Mandatory withholding (currently 24%) applied to investment income when the investor fails to provide a correct Taxpayer Identification Number or has been notified of underreporting by the IRS.

Investment Income Types

Qualified Dividends

Dividends from US corporations and qualified foreign corporations that meet holding period requirements. Taxed at the preferential long-term capital gains rates (0%, 15%, or 20%).

Ordinary Dividends

Dividends that don't meet the qualified dividend requirements — including REIT distributions, money market dividends, and dividends on shares held for less than the required holding period. Taxed at ordinary income rates.

Net Investment Income Tax (NIIT)

A 3.8% surtax under IRC §1411 on the lesser of net investment income or MAGI exceeding $200,000 (single) / $250,000 (MFJ). Applies to interest, dividends, capital gains, rental income, and passive activity income.

Original Issue Discount (OID)

The difference between a bond's face value and its original issue price when issued below par. Must be included in ordinary income annually as it accrues, even if no cash is received.

Market Discount

The difference between a bond's adjusted issue price and its purchase price in the secondary market when bought below the adjusted issue price. Accrued market discount is taxed as ordinary income upon sale.

Bond Premium

The amount paid above a bond's par value. Can be amortized to reduce taxable interest income for taxable bonds; must be amortized for tax-exempt bonds.

Return of Capital

A distribution that represents a return of the investor's original investment, not income. Reduces cost basis rather than creating taxable income. Common in MLPs, REITs, and some funds.

Wash Sales and Constructive Sales

Wash Sale

Under IRC §1091, a sale of securities at a loss where substantially identical securities are acquired within 30 days before or after the sale. The loss is disallowed but added to the replacement security's basis.

Substantially Identical Securities

Securities that are the same or economically equivalent for wash sale purposes. The same stock is clearly identical; ETFs tracking different indices are generally not.

Constructive Sale

Under IRC §1259, a transaction that eliminates substantially all risk and opportunity for gain on an appreciated position. Treated as a sale, triggering gain recognition. Examples include shorting against the box and zero-spread collars.

Special Tax Regimes

Section 1256 Contracts

Futures and broad-based index options that receive automatic 60/40 tax treatment — 60% long-term, 40% short-term — regardless of actual holding period. Reported on Form 6781.

Passive Foreign Investment Company (PFIC)

A foreign corporation that primarily earns passive income. US holders face punitive default taxation under the excess distribution method unless they make a mark-to-market or QEF election. Reported on Form 8621.

Alternative Minimum Tax (AMT)

A parallel tax calculation under IRC §55-59 that adds back certain deductions and preference items. Taxpayers pay the higher of their regular tax or tentative minimum tax. Primary triggers for investors include ISO exercises and SALT deductions.

Kiddie Tax

Rules requiring unearned income above $2,500 (2025) for children under 19 (or full-time students under 24) to be taxed at the parent's marginal rate.

Section 1202 (QSBS)

Qualified Small Business Stock exclusion allowing up to 100% exclusion of gain (up to the greater of $10 million or 10x basis) on stock of qualifying C-corporations held for more than five years.

Regulatory Bodies and Compliance

Internal Revenue Service (IRS)

The federal agency responsible for tax collection and enforcement. Administers the Internal Revenue Code.

Securities and Exchange Commission (SEC)

The federal agency regulating securities markets, broker-dealers, investment advisors, and public company disclosures.

Financial Industry Regulatory Authority (FINRA)

A self-regulatory organization overseeing broker-dealers and registered representatives. Enforces rules on suitability, best execution, and disclosure.

Accredited Investor

An individual with net worth exceeding $1 million (excluding primary residence) or income exceeding $200,000 ($300,000 with spouse) in each of the two most recent years. Required for participation in most private placements and hedge funds.

Regulation D

SEC rules governing private placement exemptions from securities registration. Rule 506(b) allows up to 35 non-accredited investors; Rule 506(c) allows general solicitation but restricts to accredited investors only.

Key Tax Forms

Form 1099-B

Reports proceeds from broker transactions, including sales of stocks, bonds, options, and other securities. Includes cost basis for covered securities.

Form 1099-DIV

Reports dividend income, including qualified dividends (Box 1b), capital gain distributions (Box 2a), and foreign tax paid (Box 7).

Form 1099-INT

Reports interest income, including US government interest (Box 3), tax-exempt interest (Box 8), and bond premium (Box 11).

Form 1099-OID

Reports original issue discount that must be included in income.

Form 1099-DA

New form (beginning 2025) reporting digital asset proceeds from custodial broker transactions.

Form 8949

Reports individual capital gains and losses. Part I covers short-term transactions; Part II covers long-term.

Schedule D

Summarizes capital gains and losses from Form 8949 and calculates the tax using preferential rates.

Form 4952

Calculates the investment interest expense deduction and tracks carryforwards.

Form 6781

Reports gains and losses from Section 1256 contracts and straddles.

Form 8615

Calculates the kiddie tax for children with unearned income exceeding the threshold.

Form 8621

Information return for shareholders of Passive Foreign Investment Companies (PFICs).

Form 8960

Calculates the Net Investment Income Tax (3.8% surtax).

Form 709

United States Gift (and Generation-Skipping Transfer) Tax Return. Filed when gifts to any individual exceed the annual exclusion.

Schedule B

Reports interest and ordinary dividends exceeding $1,500. Also used to disclose foreign financial accounts.