Beta (, ; uppercase , lowercase , or
cursive
Cursive (also known as script, among other names) is any style of penmanship in which characters are written joined in a flowing manner, generally for the purpose of making writing faster, in contrast to block letters. It varies in functional ...
; grc, βῆτα, bē̂ta or ell, βήτα, víta) is the second letter of the
Greek alphabet
The Greek alphabet has been used to write the Greek language since the late 9th or early 8th century BCE. It is derived from the earlier Phoenician alphabet, and was the earliest known alphabetic script to have distinct letters for vowels as ...
. In the system of Greek numerals, it has a value of 2. In
Modern Greek, it represents the
voiced labiodental fricative while in borrowed words is instead commonly transcribed as μπ. Letters that arose from beta include the Roman letter and the Cyrillic letters and .
Name
Like the names of most other Greek letters, the name of beta was adopted from the
acrophonic
Acrophony (; Greek: ἄκρος ''akros'' uppermost + φωνή ''phone'' sound) is the naming of letters of an alphabetic writing system so that a letter's name begins with the letter itself. For example, Greek letter names are acrophonic: the name ...
name of the corresponding letter in Phoenician, which was the common
Semitic
Semitic most commonly refers to the Semitic languages, a name used since the 1770s to refer to the language family currently present in West Asia, North and East Africa, and Malta.
Semitic may also refer to:
Religions
* Abrahamic religions
** ...
word ''*bait'' ('house'). In Greek, the name was ''bêta'', pronounced in Ancient Greek. It is spelled βήτα in modern monotonic orthography and pronounced .
History
The letter beta was derived from the
Phoenician letter beth .
Uses
Algebraic numerals
In the system of
Greek numerals
Greek numerals, also known as Ionic, Ionian, Milesian, or Alexandrian numerals, are a system of writing numbers using the letters of the Greek alphabet. In modern Greece, they are still used for ordinal numbers and in contexts similar to those ...
, beta has a value of 2. Such use is denoted by a number mark: Β′.
Computing
Finance
Beta is used in finance as a measure of (historical; pseudo-implied) financial asset sensitivity to the relevant benchmark index. Conditional on the benchmark index, the resulting beta value can vary considerably (S&P500 vs NASDAQ vs ETF of a specific industry).
Beta should not to be confused with standard deviation (or the semi-variance, which considers only negative returns): the preferred measure of the "riskiness" (historical volatility of returns) of a financial asset or a portfolio in isolation.
Beta can be calculated as the covariance of a financial asset (or portfolio) with its benchmark index, divided by the variance of the benchmark index.
Since the industry of finance gravitates towards return generating activities, typically the historical returns (percentage changes) are used in the calculations Beta values (among others).
There are numerous other methods a financial analyst can employ to derive Beta values if historical prices are not available.
Beta values change over time (company restructuring; industry sentiment; endo/exogenous factors). Beta values also vary, conditional on the time period used in calculating a Beta value.
Beta values can be negative, which infers the existence of financial assets which historically, tended to move in opposite directions to one another by some unit value.
It would seem these are the optimal "hedges" to offset market-draw-downs, during periods of market-stress and poor liquidity Beta values can vary dramatically, and previously low or even negative correlations converge to "1".
A beta of 1.5 implies that for every 1% change in the value of the benchmark index, the portfolio's value tends to change by 1.5%.
The greater the absolute value, the greater the implied move.
International Phonetic Alphabet
In the
International Phonetic Alphabet
The International Phonetic Alphabet (IPA) is an alphabetic system of phonetic transcription, phonetic notation based primarily on the Latin script. It was devised by the International Phonetic Association in the late 19th century as a standa ...
, Greek minuscule beta denotes a
voiced bilabial fricative
The voiced bilabial fricative is a type of consonantal sound, used in some Speech communication, spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is , and the equivalent X-SAMPA symbol is B. The offi ...
.
A superscript version may also indicate a
compressed vowel, like .
Meteorology
Beta has twice been used to
name
A name is a term used for identification by an external observer. They can identify a class or category of things, or a single thing, either uniquely, or within a given context. The entity identified by a name is called its referent. A personal ...
an Atlantic Basin
tropical cyclone
A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Dep ...
:
*
Hurricane Beta
Hurricane Beta was a compact and intense tropical cyclone that impacted the southwestern Caribbean in late October 2005. Beta was the twenty-fourth tropical cyclone, tropical storm, fourteenth tropical cyclone, hurricane, and seventh and f ...
, in
2005
*
Tropical Storm Beta The name Beta has been used for two tropical cyclones in the Atlantic Ocean.
* Hurricane Beta (2005), Category 3 hurricane that made landfall in Nicaragua
* Tropical Storm Beta (2020), tropical storm that made landfall in Texas
{{DEFAULTSORT:Be ...
, in
2020
Mathematics and science
Beta is often used to denote a variable in mathematics and physics, where it often has specific meanings for certain applications. In physics a stream of unbound energetic electrons is commonly referred to as
beta radiation or
beta rays. Decays producing electrons or their antiparticles are called
beta decays. In
regression analysis, symbolizes nonstandardized partial slope coefficients, whereas represents
standardized (standard deviation-score form) coefficients; in both cases, the coefficients reflect the change in the criterion Y per one-unit change in the value of the associated predictor X. β is also used in biology, for instance in
β-Carotene, a primary source of
provitamin A, or the
β cells
Beta cells (β-cells) are a type of cell found in pancreatic islets that synthesize and secrete insulin and amylin. Beta cells make up 50–70% of the cells in human islets. In patients with Type 1 diabetes, beta-cell mass and function are dimini ...
in
pancreatic islets, which produce
insulin
Insulin (, from Latin ''insula'', 'island') is a peptide hormone produced by beta cells of the pancreatic islets encoded in humans by the ''INS'' gene. It is considered to be the main anabolic hormone of the body. It regulates the metabolism o ...
.
β is sometimes used as a placeholder for an
ordinal number
In set theory, an ordinal number, or ordinal, is a generalization of ordinal numerals (first, second, th, etc.) aimed to extend enumeration to infinite sets.
A finite set can be enumerated by successively labeling each element with the lea ...
if α is already used. For example, the two roots of a
quadratic equation are typically labelled and .
In spaceflight,
beta angle
In orbital spaceflight, the beta angle (\boldsymbol) is the angle between a satellite's orbital plane around Earth and the geocentric position of the sun. The beta angle determines the percentage of time that a satellite in low Earth orbit (LEO) s ...
describes the angle between the orbit plane of a spacecraft or other body and the vector from the sun.
β is sometimes used to mean the
proton-to-electron mass ratio.
Rock climbing terminology
The term "
beta" refers to advice on how to successfully complete a particular climbing route, boulder problem, or crux sequence.
Slang
''Beta male'', or simply ''beta'', is a slang term for men derived from the designation for beta animals in ethology, along with its counterpart, ''
alpha male.'' The term has been used as a pejorative self-identifier among members of
manosphere communities, particularly
incels, who do not believe they are assertive or traditionally
masculine
Masculinity (also called manhood or manliness) is a set of attributes, behaviors, and roles associated with men and boys. Masculinity can be theoretically understood as socially constructed, and there is also evidence that some behaviors c ...
, and feel overlooked by women.
It is also used to negatively describe other men who are not assertive, particularly in
heterosexual relationships.
Statistics
In statistics, beta may represent
type II error, or
regression
Regression or regressions may refer to:
Science
* Marine regression, coastal advance due to falling sea level, the opposite of marine transgression
* Regression (medicine), a characteristic of diseases to express lighter symptoms or less extent ( ...
slope.
Typography
In some high-quality typesetting, especially in the French tradition, a typographic variant of the lowercase letter without a
descender
In typography and handwriting, a descender is the portion of a letter that extends below the baseline of a font.
For example, in the letter ''y'', the descender is the "tail", or that portion of the diagonal line which lies below the ''v'' ...
is used within a word for
ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...
: is printed .
In typesetting technical literature, it is a commonly made mistake to use the
German letter ß (a s–z or s–s ligature) as a replacement for β. The two letters resemble each other in some fonts, but they are unrelated.
Videotape formats
"Beta" can be used to refer to several consumer and professional videotape formats developed by Japan's
Sony Corporation. Although similarly named, they are very different in function and obsolescence.
*
Betamax was the name of a domestic videotape format developed in the 1970s and 1980s. It competed with the Video Home System (
VHS) format developed by the
Japanese Victor Company, to which it eventually succumbed. The Betamax format was also marketed
Betacord by (Sanyo); some cassettes were simply labeled "Beta", and the logo was a lower-case beta. Betamax lost in the market and is an oft-used example of a technically superior solution that failed due to market forces.
*
Betacam, including Beta SP and DigiBeta, is a family of professional videotape formats launched in 1982 that was the de facto standard for professional video, advertising, and television production through the 2000s. The formats outlasted analog
NTSC television, and their scarcity today is because the industry has moved to
HD formats.
Character encodings
* Greek Beta
*
Latin Beta
* Mathematical Beta
These characters are used only as mathematical symbols. Stylized Greek text should be encoded using the normal Greek letters, with markup and formatting to indicate text style.
References
{{DEFAULTSORT:Beta (Letter)
Greek letters
Phonetic transcription symbols