Industry WIKI

A quantitative fund is an investment fund that relies on systematic, data-driven methods, such as mathematical models, statistical techniques, AI, and machine learning, to make investment decisions, rather than fundamental human analysis. These funds are often referred to as systematic funds, and many employ factor investing strategies such as value and momentum, which are widely studied

In finance, the quick ratio, also known as the acid-test ratio, is a liquidity ratio that measures the ability of a company to use near-cash assets (or 'quick' assets) to extinguish or retire current liabilities immediately. It is the ratio between quick assets and current liabilities.

In finance, quote stuffing refers to a form of market manipulation employed by high-frequency traders (HFT) that involves quickly entering and withdrawing a large number of orders in an attempt to flood the market. This can create confusion in the market and trading opportunities for high-speed algorithmic traders. The term is relatively new to the financial market lexicon and was coined

The Rail Travel Card was a credit card administered by the Rail Travel Credit Agency headquartered at Chicago Union Station (room 436) to facilitate leisure and business travel by rail, possibly modeled on the air travel card. It was accepted by most major railroads, the prominent exceptions being New Haven and Southern Pacific.

Rain is a Middle Eastern cryptocurrency exchange company that operates through its holding company, Rain Financial Inc., which oversees Rain Management W.L.L. in Bahrain,

In finance, a Rainbow option is a derivative whose payoff depends on multiple underlying risky assets. Each underlying asset is referred to as a color of the rainbow. It contrasts with a simple option that is exposed to one source of uncertainty, such as the price of underlying asset.

A ratio spread or frontspread is a multi-leg options position. Like a vertical, the ratio spread involves buying and selling options on the same underlying security with different strike prices and the same expiration date. In this spread, the number of option contracts sold is not equal to a number of contracts bought. An unequal number of options contracts gives this spread certain u

In financial economics, rational pricing is the assumption that asset pricing models must reflect the arbitrage-free price of the asset

Real options valuation, also often termed real options analysis, (ROV or ROA) applies option valuation techniques to capital budgeting decisions. A real option itself, is the right—but not the obligation—to undertake certain business initiatives, such as deferring, abandoning, expanding, staging, or contracting a capital investment project. For example, real options valuation could exami

In accounting, reconciliation is the process of ensuring that two sets of records (usually the balances of two accounts) are in agreement. It is a general practice for businesses to create their balance sheet at the end of the financial year as it denotes the state of finances for that period. Reconciliation is used to ensure that the money leaving an account matches the actual money spe

In finance, recovery swaps, recovery locks, or recovery default swaps (RDS) are derivative contracts related to credit default swaps, and reference a bond issuance as its underlying. They are designed to provide a hedge against the uncertainty of recovery in default.

Red Dot Payment (RDP) is an online payment service provider headquartered in Singapore. The fintech company provides online payment gateway systems, payment consulting and merchant acquisition services for businesses that require the processing of online credit card transactions.

Regulation of algorithms, or algorithmic regulation, is the creation of laws, rules and public sector policies for promotion and regulation of algorithms, particularly in artificial intelligence and machine learning. For the subset of AI algorithms, the term regulation of artificial intelligence is used. The regulatory and policy landscape for artificial intelligence (AI) is an emerging

The regulation of cryptocurrency constitutes regulatory, legal and political actions taken by various governments to regulate and oversee the development and adoption of bitcoin, cryptocurrencies and blockchain technologies. Restrictions on cryptocurrency have been motivated by concerns regarding financial stability, consumer protection, national security, and enforcing laws against mon

Regulation S-K is a prescribed regulation under the US Securities Act of 1933 that lays out reporting requirements for various SEC filings used by public companies. Companies are also often called issuers (issuing or contemplating issuing shares), filers (entities that must file reports with the SEC) or registrants (entities that must register (usually shares) with the SEC).

Remitly is an American online remittance service based in Seattle, United States that offers international money transfers to over 170 countries. It was founded in 2011 by Matthew Oppenheimer, Josh Hug, and Shivaas Gulati and became publicly traded on the Nasdaq exchange in September 2021.

In mathematical finance, a replicating portfolio for a given asset or series of cash flows is a portfolio of assets with the same properties (especially cash flows). This is meant in two distinct senses: static replication, where the portfolio has the same cash flows as the reference asset (and no changes need to be made to maintain this), and dynamic replication, where the portfolio doe

A reserve currency is a foreign currency that is held by governments, central banks or other monetary authorities as part of their foreign exchange reserves. The reserve currency can be used in international transactions, international investments and all aspects of the global economy. It is often considered a hard currency or safe-haven currency.

Restricted stock, also known as restricted securities, is stock of a company that is not fully transferable (from the stock-issuing company to the person receiving the stock award) until certain conditions (restrictions) have been met. Upon satisfaction of those conditions, the stock is no longer restricted, and becomes transferable to the person holding the award. Restricted stock is of

Retail banking, also known as consumer banking or personal banking, is the provision of services by a bank to the general public, rather than to companies, corporations or other banks, which are often described as wholesale banking (corporate banking).

Return on capital (ROC), or return on invested capital (ROIC), is a ratio used in finance, valuation and accounting, as a measure of the profitability and value-creating potential of companies relative to the amount of capital invested by shareholders and other debtholders. It indicates how effective a company is at turning capital into profits.

Return on capital employed is an accounting ratio used in finance, valuation, and accounting. It is a useful measure for comparing the relative profitability of companies after taking into account the amount of capital used.

The return on equity (ROE) is a measure of the profitability of a business in relation to its equity;

Return on Tangible Equity (ROTE) is a financial performance metric that measures a company's profitability relative to its tangible common equity. Unlike Return on Equity, ROE, which includes intangible assets such as goodwill, ROTE focuses solely on the tangible portion of shareholders' equity, excluding intangible assets and preferred equity. This makes ROTE particularly useful for eva

Returns-based style analysis (RBSA) is a statistical technique used in finance to deconstruct the returns of investment strategies using a variety of explanatory variables. The model results in a strategy's exposures to asset classes or other factors, interpreted as a measure of a fund or portfolio manager's investment style. While the model is most frequently used to show an equity mutu

In finance, a reverse stock split or reverse split is a process by which shares of corporate stock are effectively merged to form a smaller number of proportionally more valuable shares.

Revolut Group Holdings Ltd, known as Revolut, is a British multinational neobank and financial technology company headquartered in London, England. It was founded in July 2015 by Nik Storonsky and Vlad Yatsenko. The company offers free and subscription‑based digital banking services, primarily through a mobile app.

Rewire by Remitly is a digital financial platform operated by the fintech company Remitly in Israel that provides online financial services tailored to migrant workers. The platform provides remittance services for workers to transfer funds back home. The Rewire by Remitly platform was originally built by the Israeli startup Rewire which was founded by Guy Kashtan, Saar Yahalom, Adi Ben

Ria Money Transfer (Ria) is an American financial services company which specializes in customer-to-customer international money transfers. It is a subsidiary of Euronet Worldwide, Inc. (NASDAQ: EEFT) and operates as part of its Cross-Border payments segment.

Risk arbitrage, also known as merger arbitrage, is an investment strategy that speculates on the successful completion of mergers and acquisitions. An investor that employs this strategy is known as an arbitrageur. Risk arbitrage is a type of event-driven investing in that it attempts to exploit pricing inefficiencies caused by a corporate event.

Risk of ruin is a concept in gambling, insurance, and finance relating to the likelihood of losing all one's investment capital or extinguishing one's bankroll below the minimum for further play. For instance, if someone bets all their money on a simple coin toss, the risk of ruin is 50%. In a multiple-bet scenario, risk of ruin accumulates with the number of bets: each play increases th

Risk parity (or risk premia parity) is an approach to investment management which focuses on allocation of risk, usually defined as volatility, rather than allocation of capital. The risk parity approach asserts that when asset allocations are adjusted (leveraged or deleveraged) to the same risk level, the risk parity portfolio can achieve a higher Sharpe ratio and can be more resistant

In finance, risk reversal (also known as a conversion when an investment strategy) can refer to a measure of the volatility skew or to a trading strategy.

Risk-adjusted return on capital (RAROC) is a risk-based profitability measurement framework for analysing risk-adjusted financial performance and providing a consistent view of profitability across businesses. The concept was developed by Bankers Trust and principal designer Dan Borge in the late 1970s. Note, however, that increasingly return on risk-adjusted capital (RORAC) is used as a

A risk-free bond is a theoretical bond that repays interest and principal with absolute certainty. The rate of return would be the risk-free interest rate. It is primary security, which pays off 1 unit no matter state of economy is realized at time

The risk-free rate of return, usually shortened to the risk-free rate, is the rate of return of a hypothetical investment with scheduled payments over a fixed period of time that is assumed to meet all payment obligations.

In mathematical finance, a risk-neutral measure (also called an equilibrium measure, or equivalent martingale measure) is a probability measure such that each share price is exactly equal to the discounted expectation of the share price under this measure.

Robo-advisors or robo-advisers are financial advisers that provide personalized financial advice and investment management online with moderate to minimal human intervention. A robo-advisor provides digital financial advice that is personalised based on mathematical rules or algorithms. These algorithms are designed by human financial advisors, investment managers and data scientists, an

In the United States, an ABA routing transit number (ABA RTN) is a nine-digit code printed on the bottom of checks to identify the financial institution on which it was drawn. The American Bankers Association (ABA) developed the system in 1910 to facilitate the sorting, bundling, and delivering of paper checks to the drawer's (check writer's) bank for debit to the drawer's account.

Royal Mint Gold was a digital gold currency and a cryptocurrency backed by gold reserves in the UK Royal Mint. The Royal Mint launched a digitized token called RMG, representing one gram of physical gold per token, in 2016. It began testing blockchain transactions in April 2017. The first test transaction was in August 2017. The rollout was originally scheduled to occur by the end of 20

S&P 500 futures are financial futures which allow an investor to hedge with or speculate on the future value of various components of the S&P 500 Index market index. S&P 500 futures contracts were first introduced by the Chicago Mercantile Exchange in 1982. The CME added the e-mini option in 1997. The bundle of stocks in the S&P 500 is, per the name, composed of stocks of 500 large compa

SafeMoon LLC was an American cryptocurrency and blockchain company created in March 2021. The company created the SafeMoon token (SFM) which traded on the BNB Chain blockchain. The token charged a 10% fee on transactions, with 5% redistributed (or reflected) to token holders and 5% directed to wallets in a different currency, Binance Coin (BNB), controlled by the coin's authors. The toke

Sage Pay was a payment processing service operated by Sage Group between 2006 and 2020. Originally founded as Protx, the company provided online, telephone, and point-of-sale payment solutions to small and medium-sized businesses across the United Kingdom, Ireland, Germany, Spain, South Africa, and the United States.

The colón is the currency of El Salvador, used de jure since 1892. In 2001 it was replaced de facto by the U.S. dollar during the presidency of Francisco Flores. The colón was subdivided into 100 centavos and its ISO 4217 code is SVC, which didn't deprecate as a historical code. The plural is "colones" in Spanish and the currency was named after Christopher Columbus, known as Cristóbal C

Samsung Wallet (Korean: 삼성 월렛, or simply Wallet) is a digital wallet platform developed by Samsung. It is available for the Samsung Galaxy-exclusive One UI operating system, and was announced on February 9, 2022, at the February 2022 Galaxy Unpacked event. It combines both Samsung Pay and Samsung Pass.

San Isidro (Spanish: [ˌsan iˈsidɾo]; lit. 'Saint Isidore') is a district of Lima, Peru. Created in 1931, it is an upscale part of the city's west central area, with about 600 meters of coastline. In recent years, it has become a major financial quarter, as many banks and businesses left downtown Lima to set up their headquarters in modern office blocks. It is inhabited by mostly upper mi

A savings account is a bank account at a retail bank. Common features include a limited number of withdrawals, a lack of checks and linked debit card facilities, limited transfer options and the inability to be overdrawn. Traditionally, transactions on savings accounts were widely recorded in a passbook, and were sometimes called passbook savings accounts, and bank statements were not pr

SEC Rule 10b-5, codified at 17 CFR 240.10b-5, is one of the most important rules targeting securities fraud in the United States. It was promulgated by the U.S. Securities and Exchange Commission (SEC), pursuant to its authority granted under § 10(b) of the Securities Exchange Act of 1934. The rule prohibits any act or omission resulting in fraud or deceit in connection with the purchase

SEC Rule 10b5-1, codified at 17 CFR 240.10b5-1, is a regulation enacted by the United States Securities and Exchange Commission (SEC) in 2000. The SEC states that Rule 10b5-1 was enacted in order to resolve an unsettled issue over the definition of insider trading, which is prohibited by SEC Rule 10b-5.

The secondary market, also called the aftermarket, is the financial market in which previously issued financial instruments such as shares, bonds, options, and futures are bought and sold. The initial sale of the security by the issuer to a purchaser, who pays proceeds to the issuer, is the primary market. All sales after the initial sale of the security are sales in the secondary market

Sector rotation is a theory of stock market trading patterns.

A secured loan is a loan in which the borrower pledges some asset (e.g. a car or property) as collateral for the loan, which then becomes a secured debt owed to the creditor who gives the loan. The debt is thus secured against the collateral, and if the borrower defaults, the creditor takes possession of the asset used as collateral and may sell it to regain some or all of the amount ori

Securities market participants in the United States include corporations and governments issuing securities, persons and corporations buying and selling a security, the broker-dealers and exchanges which facilitate such trading, banks which safe keep assets, and regulators who monitor the markets' activities. Investors buy and sell through broker-dealers and have their assets retained b

Securities Transaction Tax (STT) is a tax payable in India on the value of securities (excluding commodities and currency) transacted through a recognised stock exchange. As of 2016, it is 0.1% for delivery based equity trading.

Securitization is the financial practice of pooling contractual debt obligations (such as residential mortgages, commercial mortgages, auto loans, or credit card debt) and selling their associated cash flows to investors. The financial instruments sold in such transactions are known as securities, types of which include bonds, pass-through securities, and collateralized debt obligations

A security is a tradable financial asset. The term commonly refers to any form of financial instrument, but its legal definition varies by jurisdiction. In some countries and languages people commonly use the term "security" to refer to any form of financial instrument, even though the underlying legal and regulatory regime may not have such a broad definition. In some jurisdictions the

A security token offering (STO) / tokenized IPO is a type of public offering in which tokenized digital securities, known as security tokens, are sold in security token exchanges. Tokens can be used to trade real financial assets such as equities and fixed income, and use a blockchain virtual ledger system to store and validate token transactions.

Segregated Witness (SegWit), formally known as Segregated Witness (Consensus layer), is an implemented soft fork change in the transaction format of bitcoin.

Sell in May and go away is an investment strategy for stocks based on a theory (sometimes known as the Halloween indicator) that the period from November to April inclusive has significantly stronger stock market growth on average than the other months. In such strategies, stock holdings are sold or minimized at about the start of May and the proceeds held in cash (e.g. a money market fu

Session is an Australian, currently Switzerland-based, cross-platform end-to-end encrypted instant messaging application emphasizing user confidentiality and anonymity. Developed and maintained by the non-profit The Session Technology Foundation, it employs a blockchain-based decentralized network for transmission. Users can send one-to-one and group messages, including various media typ

In law, set-off or netting is a legal technique applied between persons or businesses with mutual rights and liabilities, replacing gross positions with net positions. It permits the rights to be used to discharge the liabilities where cross claims exist between a plaintiff and a respondent, the result being that the gross claims of mutual debt produce a single net claim. The net claim i

Settlement risk, also known as delivery risk or counterparty risk, is the risk that a counterparty (or intermediary agent) fails to deliver a security or its value in cash as per agreement after the first party has delivered the security or cash value. The term covers factors incidental to the settlement process that may suspend or prevent a trade from completing, even should the partie

Shape risk in finance is a type of basis risk when hedging a load profile with standard hedging products having a lower granularity. In other words, a commodity supplier wants to pre-purchase supplies for expected demand, but can only buy in fixed amounts that are bigger or smaller than the demand forecasted. This means it has to either over order or under order and make up the differe

ShapeShift AG was a cryptocurrency exchange which operated from 2014 to 2021 and was headquartered in Switzerland.

Share repurchase, also known as share buyback or stock buyback, is the reacquisition by a company of its own shares. It is an alternative way of returning money to shareholders than dividends. After a repurchase event, the company's stock price is now proportionally higher because of the smaller number of shares outstanding. Repurchases allow stockholders to potentially reduce taxes, by

In finance, the Sharpe ratio (also known as the Sharpe index, the Sharpe measure, and the reward-to-variability ratio) measures the performance of an investment such as a security or portfolio compared to a risk-free asset, after adjusting for its risk. It is defined as the difference between the returns of the investment and the risk-free return, divided by the standard deviation of the

Shetab (Persian: شتاب, lit. 'Acceleration'), officially the Interbank Information Transfer Network (Persian: شبکه تبادل اطلاعات بین بانکی), is an electronic banking clearance and automated payments system used in Iran. The system was introduced in 2002 with the intention of creating a uniform backbone for the Iranian banking system to handle ATM, EFTPOS and other card-based transactions.

Shop Pay (also known as Shop, and formerly known as Shopify Pay) is a checkout and payment method developed by Shopify. The service allows users to securely store shipping and billing information in their Shop account, enabling one-click checkouts across online stores that offer Shop Pay.

In finance, being short in an asset means investing in such a way that the investor will profit if the market value of the asset falls. This is the opposite of the more common long position, where the investor will profit if the market value of the asset rises. An investor that sells an asset short is, as to that asset, a short seller.

SIA S.p.A. is an Italian company operating in the area of ICT, providing services to the banking and finance sector in addition to platforms for financial markets and e-payment services.

Silvergate Bank was a California bank founded in 1988. The company began providing services for cryptocurrency users in 2016, and conducted an IPO in 2019.

The Single Euro Payments Area (SEPA) is a payment-integration system of the European Union that makes cross-border bank transfers in euros as fast, cheap, and simple as domestic payments. It allows individuals and businesses to make cashless euro transfers to any account within the zone using a single bank account and an International Bank Account Number, under the same basic conditions

In finance, a single-stock future (SSF) is a type of futures contract between two parties to exchange a specified number of stocks in a company for a price agreed today (the futures price or the strike price) with delivery occurring at a specified future date, the delivery date. The contracts can be later traded on a futures exchange.

Skrill is part of Paysafe Limited, a global payments platform. It is one of Paysafe's digital wallet brands and was established in 2001 to offer multiple online payment and money transfer services. The company facilitates multiple payment options including card payments, bank transfers and local payment methods. The funds in a Skrill account can then be used to pay merchants and other S

In finance and the stock market, slippage is the difference between the execution price expected by the trader (usually the one indicated by the trading software) and the one at which the transaction actually happens. Market impact, liquidity, and frictional costs may contribute to slippage.

A smart card (SC), chip card, or integrated circuit card (ICC or IC card), is a card used to control access to a resource. It is typically a plastic credit card-sized card with an embedded integrated circuit (IC) chip. Many smart cards include a pattern of metal contacts to electrically connect to the internal chip. Others are contactless, and some are both. Smart cards can provide perso

A smart contract is a computer program or a transaction protocol that is intended to automatically execute, control or document events and actions according to the terms of a contract or an agreement. The objectives of smart contracts are the reduction of need for trusted intermediators, arbitration costs, and fraud losses, as well as the reduction of malicious and accidental exceptions.

SMS banking is a form of mobile banking. It is a facility used by some banks or other financial institutions to send messages (also called notifications or alerts) to customers' mobile phones using SMS messaging, or a service provided by them which enables customers to perform some financial transactions using SMS.

Social trading is a form of investing that allows investors to observe the trading behavior of their peers and expert traders. The primary objective is to follow their investment strategies using copy trading or mirror trading. Social trading requires little or no knowledge about financial markets.

JVL Ventures, LLC d/b/a Softcard (formerly Isis Mobile Wallet), was a joint venture between AT&T, T-Mobile and Verizon which produced a mobile payments platform known as Softcard, which used near-field communication (NFC) technology to allow users to pay for items at stores and restaurants with credit and debit card credentials stored on their smartphones. The partnership was first annou

Solana is a public blockchain platform that uses a proof-of-stake consensus mechanism and provides smart contract functionality. The platform's native cryptocurrency is SOL. Solana was founded in 2018 by Toly Yakovenko and Raj Gokal, and the network was launched in March 2020 by their San Francisco-based company, Solana Labs.

Solidity is a programming language for implementing smart contracts on various blockchain platforms, most notably Ethereum. Solidity is licensed under GNU General Public License v3.0. Solidity was designed by Gavin Wood and developed by Christian Reitwiessner, Alex Beregszaszi, and several former Ethereum core contributors. Programs in Solidity run on Ethereum Virtual Machine or on compa

Sort codes are the domestic bank codes used to route money transfers between financial institutions in the United Kingdom, and formerly in Ireland. They are six-digit hierarchical numerical addresses that specify clearing banks, clearing systems, regions, large financial institutions, groups of financial institutions and ultimately resolve to individual branches. In the UK they continue

The Sortino ratio measures the risk-adjusted return of an investment asset, portfolio, or strategy. It is a modification of the Sharpe ratio but penalizes only those returns falling below a user-specified target or required rate of return, while the Sharpe ratio penalizes both upside and downside variance equally. Though both ratios measure an investment's risk-adjusted return, they do s

A Spahn tax is a type of currency transaction tax that is meant to be used for the purpose of controlling exchange-rate volatility. This idea was proposed by Paul Bernd Spahn in 1995.

In finance, speculation is the purchase of an asset (a commodity, goods, or real estate) with the hope that that asset will become more valuable in a brief amount of time.

Spoofing is a disruptive algorithmic trading activity employed by traders to outpace other market participants and to manipulate markets. Spoofers feign interest in trading futures, stocks, and other products in financial markets creating an illusion of the demand and supply of the traded asset. In an order driven market, spoofers post a relatively large number of limit orders on one sid

Sports betting is the activity of predicting sports results and placing a wager on the outcome.

In finance, a spot contract, spot transaction, or simply spot, is a contract of buying or selling a commodity, security or currency for immediate settlement (payment and delivery) on the spot date, which is normally two business days after the trade date. The settlement price (or rate) is called spot price (or spot rate). A spot contract is in contrast with a forward contract or futures

In finance, a spread option is a type of option where the payoff is based on the difference in price between two underlying assets. For example, the two assets could be crude oil and heating oil; trading such an option might be of interest to oil refineries, whose profits are a function of the difference between these two prices. Spread options are generally traded over the counter, rath

In finance, a spread trade (also known as a relative value trade) is the simultaneous purchase of one security and sale of a related security, called legs, as a unit. Spread trades are usually executed with options or futures contracts as the legs, but other securities are sometimes used. They are executed to yield an overall net position whose value, called the spread, depends on the di

Square is a point-of-sale system for sellers with physical or online stores. Launched in 2009 by Block, Inc. (formerly Square, Inc.), it enables merchants to accept card payments and manage business operations. As of 2024, Square is the U.S. market leader in point-of-sale systems, serving 4 million sellers and processing $228bn annually.

Squarepoint Capital ("Squarepoint") is a global investment management firm headquartered in New York City & London. The firm is known for its quantitative finance approach to investing. Squarepoint has additional offices in Bangalore, Boston, Dubai, Geneva, Hong Kong, Houston, Jersey, London, Madrid, Montreal, New York, Paris, Singapore, and Zug.

A squeeze-out or squeezeout, sometimes synonymous with freeze-out, is the compulsory sale of the shares of minority shareholders of a joint-stock company for which they receive a fair cash compensation.

A stablecoin is a type of cryptocurrency that aims to maintain a stable value relative to a specified asset, a pool or basket of assets. The specified asset might refer to fiat currency, commodity, or other cryptocurrencies. Despite the name, stablecoins are not necessarily stable. Stablecoins rely on stabilization tools such as reserve assets or algorithms that match supply and demand

In the context of operational risk, the standardized approach or standardised approach is a set of operational risk measurement techniques proposed under Basel II capital adequacy rules for banking institutions.

In finance, statistical arbitrage (Stat Arb or StatArb) is a class of short-term financial trading strategies that employ mean reversion models involving broadly diversified portfolios of securities (hundreds to thousands) held for short periods of time (generally seconds to days). These strategies are supported by substantial mathematical, computational, and trading platforms.

Stellar, or Stellar Lumens (symbol: XLM), is a cryptocurrency protocol which allows transactions between any pair of currencies.

The STET-CORE system is a French interbank automated clearing house. STET SA, whose name refers to Systèmes Technologiques d'Echange et de Traitement (lit. 'Exchange and Processing Technological Systems'), is the system's operating company, based in Paris La Défense. CORE, whose name refers to COmpensation REtail (compensation being French for clearing), is the main platform developed by

In statistics, stochastic volatility models are those in which the variance of a stochastic process is itself randomly distributed. They are used in the field of mathematical finance to evaluate derivative securities, such as options. The name derives from the models' treatment of the underlying security's volatility as a random process, governed by state variables such as the price leve