Beta (, ; uppercase, lowercase , or cursive ; or ) is the 2nd letter of the Greek alphabet. In the system of Greek numerals, it has a value of 2. In Ancient Greek, beta represented the voiced bilabial plosive. 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 ⟨B⟩ and the Cyrillic letters ⟨Б⟩ and ⟨В⟩.

Name

Like the names of most other Greek letters, the name of beta was adopted from the acrophonic name of the corresponding letter in Phoenician, which was the common Semitic word *bayt ('house', compare bayt and báyit). In Greek, the name was βῆτα 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. The letter Β had the largest number of highly divergent local forms. Besides the standard form (either rounded or pointed, ), there were forms as varied as (Gortyn), and (Thera), (Argos), (Melos), (Corinth), (Megara, Byzantium), and (Cyclades).

Uses

Algebraic numerals

In the system of Greek numerals, 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 investment portfolio risk. Beta in this context is calculated as the covariance of the portfolio's returns with its benchmark's returns, divided by the variance of the benchmark's returns. A beta of 1.5 means that for every 1% change in the value of the benchmark, the portfolio's value tends to change by 1.5%.

International Phonetic Alphabet

In the International Phonetic Alphabet, Greek minuscule beta denotes a voiced bilabial fricative. A superscript version may also indicate a compressed vowel, like.

Meteorology

Beta has twice been used to name an Atlantic Basin tropical cyclone:

Mathematics and science

α and β .

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, 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 slope.

Typography

In some high-quality typesetting, especially in the French tradition, a typographic variant of the lowercase letter without a descender is used within a word for ancient Greek: βίβλος is printed βίϐλος. In typesetting technical literature, it is a commonly made mistake to use the ß|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.

Unicode

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: