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The measure of an asset's risk in relation to the market (for example, the S&P500) or to an alternative benchmark or factors. Roughly speaking, a security with a beta of 1.5, will have move, on average, 1.5 times the market return. [More precisely, that stock's excess return (over and above a short-term money market rate) is expected to move 1.5 times the market excess return).] According to asset pricing theory, beta represents the type of risk, systematic risk, that cannot be diversified away. When using beta, there are a number of issues that you need to be aware of: (1) betas may change through time; (2) betas may be different depending on the direction of the market (i.e. betas may be greater for down moves in the market rather than up moves); (3) the estimated beta will be biased if the security does not frequently trade; (4) the beta is not necessarily a complete measure of risk (you may need multiple betas). Also, note that the beta is a measure of co-movement, not volatility. It is possible for a security to have a zero beta and higher volatility than the market.


A measure of a security's or portfolio's volatility. A beta of 1 means that the security or portfolio is neither more nor less volatile or risky than the wider market. A beta of more than 1 indicates greater volatility and a beta of less than 1 indicates less. Beta is an important component of the Capital Asset Pricing Model, which attempts to use volatility and risk to estimate expected returns.


A mathematical measure of the sensitivity of rates of return on a portfolio or a given stock compared with rates of return on the market as a whole. A high beta (greater than 1.0) indicates moderate or high price volatility. A beta of 1.5 forecasts a 1.5% change in the return on an asset for every 1% change in the return on the market. High-beta stocks are best to own in a strong bull market but are worst to own in a bear market. See also alpha, capital-asset pricing model, characteristic line, portfolio beta.


Beta is a measure of an investment's relative volatility. The higher the beta, the more sharply the value of the investment can be expected to fluctuate in relation to a market index.

For example, Standard & Poor's 500 Index (S&P 500) has a beta coefficient (or base) of 1. That means if the S&P 500 moves 2% in either direction, a stock with a beta of 1 would also move 2%.

Under the same market conditions, however, a stock with a beta of 1.5 would move 3% (2% increase x 1.5 beta = 0.03, or 3%). But a stock with a beta lower than 1 would be expected to be more stable in price and move less. Betas as low as 0.5 and as high as 4 are fairly common, depending on the sector and size of the company.

However, in recent years, there has been a lively debate about the validity of assigning and using a beta value as an accurate predictor of stock performance.

References in periodicals archive ?
The preferred ligands of the mu receptor are beta-endorphin and enkephalin, those of the delta receptor are the leu- and met-enkephalines, and dynorphins A and B are those preferred by kappa receptors.
Ethanol induces apoptotic death of beta-endorphin neurons in the rat hypothalamus by a TGF-beta 1-dependent mechanism.
Blocking the effects of beta-endorphin with naloxone, the same drug used to treat heroin overdoses, also blocked the boost in the mice's pain threshold, the researchers found.
Maternal plasma concentrations of CRH and beta-endorphin were seen to have a correlated rise during labour which was thought to be a response to pain perception (Mauri et al.
Hormone Function Oxytocins Uterotonic effect Antianxiolytic impact Facilitates the expression of maternal behaviour Promotes the trust levels Helps improve the memory for facial identity Beta-endorphin Natural pain killer Decreases stress Makes the baby alert Boosts the maternal-child bond Induces bond between the partners Catecholamines Triggers survival behaviours (adrenalin, Decreases psychological distress noradrenalin) Creates energy boost Triggers the foetus ejection reflex Creates maternal-child bond Prostaglandins Makes effective uterine contractions Facilitates cervical ripening and dilatation Prolactin Regulates maternal behaviours Contributes to the direct paternal care Decreases the level of anxiety and stress Table 2.
High levels of beta-endorphin in hypophyseal portal blood.
In these individuals, food triggers the release of dopamine and beta-endorphin within the nucleus accumbens and ventral tegmental area.
Beta-endorphin, Metenkephalin and corresponding opioid receptors within synovium of patients with joint trauma, osteoarthritis and rheumatoid arthritis.
Characterization of the effects of acute ethanol administration on the release of beta-endorphin peptides by the rat hypothalamus.
The Additive Synthesis of a Regulatory Peptide in Vivo: The Administration of a Vaccinal Francisella tularensis Strain That Produces Beta-Endorphin," Biull Eksp Biol Med, August 1993.
The main groups of opioid peptides, enkephalins, dynorphins and beta-endorphin, are derived from proenkephalin, prodynorphin and proopiomelanocortin, respectively (20).
Beta-endorphin and stress hormones in patients affected by osteoarthritis undergoing thermal mud therapy.