Glossary

Every term behind the headline.

Plain-English definitions of the SEC filings, FDA milestones, corporate actions, options, short selling and market structure terms behind market-moving news. Each entry gives a one-line definition, why it moves stocks, a worked example, and links to the live Quantisnow feeds where the term shows up.

207 terms Glossary as Markdown Investing guides

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Insiders and ownership 13

Earnings and fundamentals 15

Dividends 10

Corporate actions 12

Mergers and acquisitions 10

IPOs and offerings 16

Analyst ratings 12

Short selling 12

A to Z

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0DTE options: Options traded on the same day they expire, most commonly on the S&P 500 index (SPX) and major index ETFs such as SPY and QQQ.
510(k) clearance: FDA clearance to market a medical device shown to be substantially equivalent to a legally marketed device already on the market.
8-K Item 1.01: Entry into a Material Definitive Agreement: The 8-K item a company uses to disclose that it signed a material agreement outside the ordinary course of business, such as a merger or credit deal.
8-K Item 1.02: Termination of a Material Definitive Agreement: The 8-K item a company uses to disclose that a material agreement was terminated, other than by expiring on its stated terms.
8-K Item 1.03: Bankruptcy or Receivership: The 8-K item a company files to disclose a bankruptcy filing, receivership, or similar proceeding involving the company or its parent.
8-K Item 1.05: Material Cybersecurity Incidents: The 8-K item a company files within four business days of determining that a cybersecurity incident is material.
8-K Item 2.01: Completion of Acquisition or Disposition of Assets: The 8-K item a company files when it closes the purchase or sale of a significant amount of assets, including a business.
8-K Item 2.02: Results of Operations and Financial Condition: The 8-K item a company uses to furnish an earnings release or other public announcement of results for a completed period.
8-K Item 2.03: Creation of a Direct Financial Obligation: The 8-K item a company files when it takes on a material direct financial obligation, such as a loan or bond, or an off-balance sheet obligation.
8-K Item 2.05: Costs Associated with Exit or Disposal Activities: The 8-K item a company files when it commits to a restructuring, such as layoffs or closures, that will cause material charges under GAAP.
8-K Item 2.06: Material Impairments: The 8-K item a company files when it concludes that a material impairment charge to its assets, such as goodwill, is required under GAAP.
8-K Item 3.01: Notice of Delisting or Failure to Satisfy a Listing Rule: The 8-K item a company files after an exchange notifies it that it no longer meets a listing standard, or when it moves or ends its listing.
8-K Item 3.02: Unregistered Sales of Equity Securities: The 8-K item a company files when it sells equity securities in a private, unregistered deal above certain size thresholds.
8-K Item 4.01: Changes in Registrant's Certifying Accountant: The 8-K item a company files when its independent auditor resigns, declines to stand for reappointment, or is dismissed, or a new one is engaged.
8-K Item 4.02: Non-Reliance on Previously Issued Financial Statements: The 8-K item a company files when its previously issued financial statements should no longer be relied on because of an error, signaling a restatement.
8-K Item 5.02: Departure or Appointment of Directors and Officers: The 8-K item a company files when a director or key executive leaves or is appointed, or when it adopts or changes material executive pay arrangements.
8-K Item 5.07: Submission of Matters to a Vote of Security Holders: The 8-K item a company files to report the results of shareholder votes, usually within four business days after its annual or special meeting.
8-K Item 7.01: Regulation FD Disclosure: The 8-K item a company uses to furnish information publicly under Regulation FD, such as investor presentations or updated guidance.
8-K Item 8.01: Other Events: The catch-all 8-K item companies use to voluntarily report events they consider important to shareholders that no other item requires.

A

Abbreviated New Drug Application (ANDA): The FDA application used to approve a generic drug by showing it is bioequivalent to an already approved brand-name drug.
Accelerated approval: An FDA pathway approving drugs for serious conditions based on a surrogate endpoint, with confirmatory trials required to verify clinical benefit.
Activist investor: An investor who buys a meaningful stake in a public company to push for changes such as a sale, board seats, buybacks or new management.
After-hours trading: Trading in US stocks after the 4:00 p.m. ET close, usually until 8:00 p.m. ET, when earnings and other news often break.
Analyst downgrade: A sell-side analyst's move to a less favorable rating on a stock, such as from Buy to Hold, usually published with a lower price target and rationale.
Analyst upgrade: A sell-side analyst's move to a more favorable rating on a stock, such as from Hold to Buy, usually published with a new price target and thesis.
At the money (ATM): Describes an option whose strike price equals or sits very close to the current price of the underlying stock.
At-the-market (ATM) offering: A way for a public company to sell new shares gradually into the open market at prevailing prices through a sales agent, off a shelf registration.

B

Beneficial owner: A person who has or shares voting or investment power over a security, directly or indirectly, even if the shares are held in another name.
Bid-ask spread: The gap between the highest price a buyer will pay (the bid) and the lowest price a seller will accept (the ask) for a security.
Biologics License Application (BLA): The application a company submits to the FDA to market a biologic, such as an antibody, vaccine or gene therapy, in the United States.
Blackout period: A window around quarter end and earnings when a company's insider trading policy bars officers, directors and some employees from trading its stock.
Borrow fee: The annualized interest rate a short seller pays to borrow shares, charged daily and rising sharply when shares are scarce.
Breakthrough therapy designation: An FDA designation that speeds development of a drug for a serious condition when early clinical data show substantial improvement over existing therapy.
Buy rating: An analyst recommendation that a stock is expected to outperform or deliver meaningful positive returns over the rating horizon, usually 12 months.

C

Call option: A contract giving the buyer the right, but not the obligation, to buy a stock at a set price on or before a set date.
Catalyst: An event or piece of news that causes, or is expected to cause, a significant move in a stock's price.
Chapter 11 bankruptcy: A US bankruptcy process that lets a company keep operating while it restructures its debts under court supervision through a plan of reorganization.
Chapter 7 bankruptcy: A US bankruptcy process in which a company stops operating and a court-appointed trustee sells its assets to repay creditors in priority order.
Complete response letter (CRL): A letter from the FDA stating it cannot approve a drug or biologic application in its current form and explaining the deficiencies to fix.
Consensus estimate: The average or median of sell-side analysts' forecasts for a company's earnings, revenue or other metric for a given period.
Convertible notes: Debt securities that pay interest and can be converted into a set number of the issuer's shares, usually at a premium to the share price at issue.
Covered call: An options strategy where an investor who owns at least 100 shares sells a call against them to collect premium, capping upside above the strike.

D

Dark pool: A private trading venue that matches buy and sell orders without displaying quotes publicly, reporting trades only after they execute.
Days to cover (short interest ratio): Short interest divided by average daily trading volume, estimating how many days it would take short sellers to buy back all their shares.
De-SPAC: The merger in which a SPAC combines with a private operating company, turning that company into a publicly traded business.
Deal spread: The gap between an acquisition target's market price and the value of the offer, reflecting the market's view of closing risk and time.
Declaration date: The date a company's board announces a dividend, setting its amount, ex-dividend date, record date and payment date.
DEF 14A (proxy statement): The definitive proxy statement a public company files before a shareholder meeting, covering board elections, executive pay and other voting items.
Delisting: The removal of a company's stock from a national exchange, either voluntarily or because it failed listing standards, often leaving it to trade OTC.
Delta: How much an option's price is expected to change for a $1 move in the underlying stock, from 0 to 1 for calls and 0 to -1 for puts.
Dilution: The reduction in existing shareholders' ownership percentage and per-share claims on earnings when a company issues new shares.
Direct listing: A way to go public by listing existing shares on an exchange without an underwritten IPO, with the opening price set by the market.
Dividend: A distribution of a company's profits or cash to shareholders, usually paid in cash on a regular schedule after being declared by the board.
Dividend cut: A reduction or suspension of a company's regular dividend by its board, usually to preserve cash when earnings or cash flow weaken.
Dividend reinvestment plan (DRIP): A program that automatically uses an investor's cash dividends to buy more shares of the same stock, often including fractional shares.
Dividend yield: A stock's annual dividend per share divided by its current share price, expressed as a percentage of the price.

E

Earnings call: A conference call or webcast where company management discusses quarterly results and guidance and takes questions from analysts.
Earnings per share (EPS): A company's net income available to common shareholders divided by its weighted average shares outstanding, reported as basic and diluted figures.
Earnings surprise (beat or miss): The difference between a company's reported earnings and the analyst consensus estimate, described as a beat when above and a miss when below.
EBITDA: Earnings before interest, taxes, depreciation and amortization, a common proxy for operating profit before financing and non-cash charges.
EDGAR: The SEC's electronic system where public companies, insiders and funds submit filings and where anyone can read them for free.
Ex-dividend date: The first trading day on which a stock trades without the right to its next dividend; buyers on or after this date do not receive it.
Expiration date: The last day an options contract can be traded or exercised, after which it either settles or expires worthless.

F

Failure to deliver (FTD): A trade in which the seller does not deliver the shares to the buyer by the settlement date, currently one business day after the trade (T+1).
Fast track designation: An FDA designation that speeds development of drugs for serious conditions with unmet need, adding FDA contact and rolling review of the application.
FDA advisory committee (AdCom): A panel of outside experts that reviews a drug or device application in a public meeting and votes on questions such as whether benefits outweigh risks.
FINRA: The self-regulatory organization that oversees US broker-dealers, licenses their representatives and collects short interest and off-exchange trade data.
Follow-on offering: A sale of additional shares by a company that is already public, used to raise more capital or let existing holders sell stock.
Form 10-K: The audited annual report US public companies file with the SEC, covering the business, risk factors, MD&A and full financial statements.
Form 10-Q: The quarterly report US public companies file with the SEC for each of the first three fiscal quarters, with unaudited financial statements and MD&A.
Form 13F: A quarterly SEC report of US equity holdings by investment managers with $100 million or more in 13(f) securities, due 45 days after quarter end.
Form 144: A notice filed with the SEC when an affiliate or holder of restricted stock plans to sell shares under Rule 144 above set size thresholds.
Form 15: The SEC filing a company uses to terminate registration of a class of securities or suspend its periodic reporting obligations.
Form 20-F: The annual report foreign private issuers file with the SEC, roughly equivalent to a 10-K, due within four months of fiscal year-end.
Form 25: The SEC filing that removes a class of securities from listing on a national exchange, made by either the exchange or the company.
Form 3: The initial SEC statement of beneficial ownership filed by a company's officers, directors and 10% holders when they first become insiders.
Form 4: The SEC filing that reports a change in an insider's holdings, such as a purchase, sale, option exercise or grant, generally within two business days.
Form 424B prospectus: A prospectus filed with the SEC under Rule 424(b), typically the final pricing terms of an IPO or a takedown from a shelf registration.
Form 5: An annual SEC filing where insiders report exempt or small transactions that were not already disclosed on Form 4, due 45 days after fiscal year end.
Form 6-K: The SEC form foreign private issuers use to furnish material information they publish at home, such as earnings releases and major announcements.
Form 8-K: The SEC "current report" a public company files to disclose material events, generally within four business days of the event.
Form D: The SEC notice a company files after first selling securities in an exempt private offering under Regulation D, disclosing the amount raised.
Form F-1: The SEC registration statement foreign private issuers use for an IPO or other securities offering in the US, the foreign counterpart to Form S-1.
Form NT 10-K (notification of late filing): The SEC notice a company files when it cannot submit its 10-K on time, giving it a 15-calendar-day grace period under Rule 12b-25.
Form S-1: The SEC registration statement US companies use for an IPO or other securities offering when they cannot use a shorter form such as the S-3.
Form S-3: The short-form SEC registration statement seasoned public companies use to register securities, most often for shelf offerings.
Form S-4: The SEC registration statement used to register securities issued in mergers, acquisitions and exchange offers, often combined with a proxy statement.
Form S-8: The SEC registration statement companies use to register shares issued to employees and directors under stock option and equity compensation plans.
Free cash flow: The cash a company generates from operations after capital expenditures, available for debt repayment, dividends, buybacks or acquisitions.

G

Gamma: The rate at which an option's delta changes for each $1 move in the underlying stock, highest for at-the-money options near expiration.
Gap up and gap down: A price jump between sessions, when a stock opens above the prior high (gap up) or below the prior low (gap down), usually on news.
Go-shop period: A window after a merger agreement is signed during which the target may actively solicit competing bids, usually with a reduced break-up fee.
Going concern warning: A disclosure, by management or the auditor, that there is substantial doubt about a company's ability to keep operating for the next year.
Going-private transaction: A deal in which a public company's shares are bought out, often by private equity, insiders or a controlling holder, and the stock stops trading.
Greenshoe option (over-allotment): An underwriter's option to sell up to 15% more shares than planned in an offering, used to stabilize the price after trading begins.
Guidance: A company's own forecast of future results, such as revenue, EPS or margins for the next quarter or year, usually issued with earnings.

H

Hard to borrow: A stock with little lendable supply relative to short-selling demand, which brings high borrow fees and possible limits on new short sales.
Hold rating: A neutral analyst recommendation that a stock is expected to perform roughly in line with the market or its sector, without a clear reason to buy or sell.
Hostile takeover: An attempt to acquire a company against the wishes of its board, typically through a tender offer directly to shareholders or a proxy fight.

I

Implied volatility (IV): The market's forecast of how much a stock will move, expressed as an annualized percentage and backed out of current option prices.
In the money (ITM): Describes an option with intrinsic value: a call whose strike is below the stock price, or a put whose strike is above it.
Initial public offering (IPO): The first sale of a private company's shares to the public, after which the stock lists and trades on an exchange such as Nasdaq or the NYSE.
Initiation of coverage: The first research report an analyst or brokerage publishes on a company, setting an opening rating and price target.
Insider buying: Purchases of a company's stock by its officers, directors or 10% holders, reported to the SEC on Form 4 and watched as a signal of insider confidence.
Institutional ownership: The share of a company's stock held by institutions such as mutual funds, pensions, hedge funds and banks, usually estimated from 13F filings.
Investigational New Drug application (IND): The FDA filing a sponsor must have in effect before testing an unapproved drug or biologic in humans in the United States.
IPO pricing: The process by which a company and its underwriters set the final per-share price and size of an IPO, usually the evening before trading begins.
IV crush: The sharp drop in implied volatility, and in option prices, that typically follows a scheduled event like earnings or an FDA decision.

L

Letter of intent: A largely non-binding document setting out the main terms of a proposed deal, such as price and structure, before a definitive agreement is negotiated.
Level 2 quotes: Market data showing the full depth of bids and offers at multiple price levels, not just the best bid and ask.
Limit order: An order to buy or sell at a specified price or better, which controls the price but does not guarantee the order will fill.
Limit up-limit down (LULD): A US rule that sets price bands around each stock's recent average price and pauses trading for five minutes when the stock cannot trade inside them.
Lock-up period: A contractual window after an IPO or offering, commonly 180 days, during which insiders and early investors agree not to sell their shares.

M

Market capitalization: The total market value of a company's outstanding shares, calculated as the share price multiplied by the number of shares outstanding.
Market maker: A firm that continuously quotes both a buy and a sell price in a security, earning the spread in exchange for supplying liquidity.
Market order: An order to buy or sell immediately at the best available price, which guarantees execution but not the price.
Market-wide circuit breaker: A rule that halts trading in all US stocks when the S&P 500 falls 7%, 13% or 20% from the prior day's close.
MD&A (Management's Discussion and Analysis): The section of a 10-K or 10-Q where management explains results, trends, liquidity and capital resources in its own words.
Merger agreement: The binding contract between an acquirer and a target that sets the deal price, structure, closing conditions and termination rights of an acquisition.
Merger arbitrage: A strategy that buys the stock of an acquisition target after a deal is announced to capture the gap between its market price and the offer price.
Minimum bid price requirement: An exchange listing rule requiring a stock to trade at $1.00 or more, with a deficiency notice after 30 consecutive business days below it.

N

Naked short selling: Selling shares short without first borrowing them or arranging to borrow them, which can leave the buyer without delivery at settlement.
Nasdaq: A US stock exchange, launched in 1971 as the first electronic market, that lists thousands of companies across three market tiers.
NBBO (national best bid and offer): The highest bid and lowest offer for a stock across all US exchanges, the benchmark brokers use for best execution.
New Drug Application (NDA): The formal application a drugmaker submits to the FDA requesting approval to market a new small-molecule drug in the United States.
Non-GAAP earnings: Earnings figures adjusted by a company to exclude items such as stock compensation, amortization or one-time charges, which must be reconciled to GAAP.
NYSE: The New York Stock Exchange, the largest US stock exchange by listed market value, owned by Intercontinental Exchange since 2013.

O

Open interest: The total number of options contracts for a given strike and expiration that are still open and have not been closed, exercised or expired.
Option premium: The price an options buyer pays the seller for a contract, made up of intrinsic value plus time value.
Options chain: A table listing every available call and put for a stock, organized by expiration date and strike, with prices, volume and open interest.
Options volume: The number of options contracts traded during a session, for a single strike, an expiration or all of a stock's options combined.
Orphan drug designation: An FDA status for drugs treating rare diseases affecting fewer than 200,000 people in the US, bringing incentives such as 7 years of market exclusivity.
OTC markets: Trading venues outside the national exchanges where stocks trade through broker-dealer networks, mainly the OTCQX, OTCQB and Pink tiers.
Out of the money (OTM): Describes an option with no intrinsic value: a call whose strike is above the stock price, or a put whose strike is below it.
Outperform rating: An analyst rating meaning a stock is expected to deliver better returns than its sector, the market or the analyst's coverage universe; similar to Buy.
Overweight rating: An analyst rating meaning a stock is expected to beat its sector or benchmark, so investors should hold more of it than its index weight; similar to Buy.

P

Payment date: The date a company actually pays a declared dividend to eligible shareholders, usually days or weeks after the record date.
Payment for order flow: Compensation a broker receives from a market maker for routing customer orders to it for execution, common in commission-free US retail brokerage.
Payout ratio: The share of a company's earnings paid out as dividends, calculated as dividends per share divided by earnings per share.
PDUFA date: The target date by which the FDA aims to approve or reject a new drug or biologic application under the Prescription Drug User Fee Act.
Penny stock: A low-priced, usually small and thinly traded stock, defined by SEC rules generally as an equity security trading below $5 per share.
Phase 1 clinical trial: The first stage of human testing for a new drug, focused on safety, tolerability, dosing and how the body processes it, usually in a small group.
Phase 2 clinical trial: The mid-stage of drug testing in patients, designed to show early evidence that a drug works, refine the dose and further assess safety.
Phase 3 clinical trial: The large, late-stage trial that tests whether a drug works and is safe in a broad patient population, usually forming the basis for an FDA application.
PIPE (private investment in public equity): A private sale of a public company's stock or convertible securities to selected investors, usually at a discount, registered for resale later.
Poison pill (shareholder rights plan): A takeover defense that lets existing holders buy discounted shares if an investor crosses an ownership threshold, diluting the would-be acquirer.
Pre-market trading: Trading in US stocks before the 9:30 a.m. ET open, typically from 4:00 a.m. ET, with thinner liquidity and wider spreads.
Preannouncement: An early release of preliminary results or a guidance change before a company's scheduled earnings report, either positive or negative.
Premarket approval (PMA): The FDA's most rigorous review pathway for high-risk Class III medical devices, requiring scientific evidence of safety and effectiveness.
Press release: An official company announcement distributed through a newswire, used to disclose earnings, deals, trial results and other news to the public.
Price target: An analyst's estimate of where a stock will trade at a future point, usually 12 months out, used with a rating to show expected upside or downside.
Price-to-earnings ratio (P/E): A valuation multiple equal to a stock's share price divided by its earnings per share, showing how much investors pay for each dollar of profit.
Primary endpoint: The main outcome a clinical trial is designed and statistically powered to measure, used to judge whether the drug worked.
Priority review: An FDA designation that shortens the review goal for a drug application to 6 months instead of the standard 10 months.
Public float: The portion of a company's outstanding shares held by non-affiliates, excluding stock owned by officers, directors and controlling holders.
Put option: A contract giving the buyer the right, but not the obligation, to sell a stock at a set price on or before a set date.
Put/call ratio: Put options volume (or open interest) divided by call options volume, used as a gauge of bearish versus bullish positioning.

Q

Quiet period: A stretch when a company or its underwriters limit public communication, most often around an IPO or in the weeks before an earnings release.

R

Record date: The date a company uses to determine which shareholders are entitled to a dividend or other distribution, or to vote at a meeting.
Registered direct offering: A sale of shelf-registered shares directly to a small group of pre-selected investors through a placement agent, often at a discount and with warrants.
Regulation FD: The SEC rule that bars public companies from selectively disclosing material nonpublic information to analysts or investors before the public.
Regulation SHO: The SEC rule set governing US short sales, covering order marking, the locate requirement, close-outs of failed trades and the alternative uptick rule.
Reiterated rating: An analyst note confirming an existing rating on a stock without changing it, often issued after earnings or news and sometimes with a new price target.
Relative volume: A ratio comparing a stock's current trading volume to its typical volume for the same period, used to spot unusual activity.
REMS (Risk Evaluation and Mitigation Strategy): A safety program the FDA can require for a drug with serious risks, ranging from a medication guide to restricted prescribing and distribution.
Reverse merger: A transaction in which a private company becomes public by merging into an existing public company, bypassing a traditional IPO.
Reverse stock split: A corporate action that combines existing shares into fewer shares at a higher price, often used to regain compliance with exchange minimum bid rules.
Rights offering: A capital raise in which a company gives existing shareholders the right to buy new shares, usually at a discount, in proportion to their holdings.
Rule 10b5-1 trading plan: A prearranged written plan that lets insiders buy or sell stock on a set schedule, providing an affirmative defense against insider trading claims.

S

Schedule 13D: The SEC disclosure an investor must file after acquiring more than 5% of a company's voting stock with an active intent, such as seeking change.
Schedule 13G: A short-form SEC disclosure for investors who own more than 5% of a company's voting stock but hold it passively, without intent to influence control.
Schedule TO: The SEC filing made by a company or bidder launching a tender offer for a public company's securities, disclosing the offer's terms.
SEC (Securities and Exchange Commission): The US federal agency that regulates securities markets, enforces securities laws and oversees the disclosures public companies must file.
Secondary offering: A sale of a public company's shares by existing holders such as founders or private equity, with proceeds going to the sellers, not the company.
Sell rating: An analyst recommendation that a stock is expected to underperform or decline, the rarest of the standard ratings on Wall Street.
Sell-side analyst: A research analyst at a brokerage or investment bank who publishes ratings, price targets and earnings estimates on stocks for the firm's clients.
Share buyback: A company's repurchase of its own shares from the market or directly from holders, reducing shares outstanding and returning cash to investors.
Shares outstanding: The total number of a company's shares currently held by all shareholders, including insiders and institutions, excluding treasury shares.
Shelf registration: An SEC registration that lets a company register securities in advance and sell them over time, typically up to three years, as market conditions allow.
Short interest: The total number of a company's shares that have been sold short and not yet covered, reported by brokers to FINRA twice a month.
Short sale restriction (alternative uptick rule): A rule that, after a stock drops 10% or more from the prior close, lets short sales execute only above the national best bid for that day and the next.
Short seller report: A public research report from an investor who is short a stock, alleging problems such as fraud, accounting issues or overvaluation.
Short selling: Selling borrowed shares in the hope of buying them back later at a lower price, profiting from a decline in the stock.
Short squeeze: A rapid price rise driven by short sellers buying back shares to limit losses, which pushes the price higher and forces more covering.
Short volume: The number of shares sold short during a single trading day, as published daily by FINRA for trades reported to its facilities.
Small-cap stock: A stock of a company with a relatively small market capitalization, commonly defined as roughly $300 million to $2 billion.
SPAC (special purpose acquisition company): A shell company that raises cash in an IPO and places it in trust to acquire a private company, which becomes public through the merger.
Special dividend: A one-time dividend paid outside a company's regular schedule, often after an asset sale, a windfall or a buildup of excess cash.
Spin-off: A corporate action in which a company separates a business unit into a new, independently traded company and distributes its shares to existing holders.
Stock split: A corporate action that increases a company's share count by a fixed ratio and cuts the per-share price proportionally, leaving market value unchanged.
Stop-loss order: An order that becomes a market order to sell (or buy) once a stock trades at a specified stop price, used to limit losses.
Strike price: The fixed price at which an option holder can buy (call) or sell (put) the underlying stock if the option is exercised.
Supplemental NDA (sNDA): An application to change an already approved drug's NDA, most often to add a new indication, patient population, dose or formulation.

T

T+1 settlement: The US standard under which most stock trades settle one business day after the trade date, in effect since May 28, 2024.
Tender offer: A public offer to buy shares directly from a company's stockholders at a fixed price or price range, usually at a premium and for a limited time.
Termination fee (break-up fee): A payment one party to a merger agreement owes the other if the deal is terminated for specified reasons, such as accepting a better offer.
Theta: The estimated amount an option loses in value each day from the passage of time, with all other factors held constant.
Ticker change: A change to the symbol under which a company's stock trades, usually tied to a rebrand, merger, exchange move or corporate restructuring.
Topline data: The first high-level results from a clinical trial, usually covering the primary endpoint and key safety findings, released before the full dataset.
Trading halt: A temporary stop in trading of a security, called by an exchange or regulator for pending news, volatility, or regulatory concerns.

U

Underweight rating: An analyst rating meaning a stock is expected to lag its sector or benchmark, so investors should hold less of it than its index weight; similar to Sell.
Underwriter: An investment bank that manages a securities offering, buys the shares from the issuer and resells them to investors, earning a fee called the spread.
Unusual options activity: Options trading far above a contract's normal volume or open interest, often in short-dated strikes, that may signal positioning ahead of news.

V

Vega: How much an option's price is expected to change for each one-percentage-point change in implied volatility.
VWAP (volume-weighted average price): The average price a security traded at during a period, weighted by the volume at each price, usually reset each trading day.

W

Warrants: Securities issued by a company that give the holder the right to buy its shares at a set exercise price before a set expiration date.
Whisper number: An unofficial earnings expectation, often higher than the published consensus, that reflects what traders believe a company will actually report.