32-646: The BEL 20 is the benchmark stock market index of Euronext Brussels . It tracks the performance of 20 most capitalized and liquid stocks traded in Belgium. In general, the index consists of a minimum of 10 and a maximum of 20 companies traded at the Brussels Stock Exchange . Since 20 June 2011, the BEL20 has contained 20 listings, with the exception a one-month period in May–June 2018 when Ablynx stock
64-416: A , b ] {\displaystyle [a,b]} . Here d x {\displaystyle dx} is Lebesgue measure and w : Ω → R + {\displaystyle w\colon \Omega \to \mathbb {R} ^{+}} is a non-negative measurable function . In this context, the weight function w ( x ) {\displaystyle w(x)}
96-442: A stock index that complies with Sharia 's ban on alcohol, tobacco and gambling. Critics of such initiatives argue that many firms satisfy mechanical "ethical criteria" (e.g. regarding board composition or hiring practices) but fail to perform ethically with respect to shareholders (e.g. Enron ). Indeed, the seeming "seal of approval" of an ethical index may put investors more at ease, enabling scams. One response to these criticisms
128-552: A stock market index is separate from the weighting method. For example, the S&P 500 market-cap weighted index covers the 500 largest stocks from the S&P Total Market Index, but an equally weighted S&P 500 index is also available with the same coverage. Stock market indices may be categorized by their index weight methodology, or the rules on how stocks are allocated in the index, independent of its stock coverage. For example,
160-511: A subset of a stock market. It helps investors compare current stock price levels with past prices to calculate market performance. Two of the primary criteria of an index are that it is investable and transparent : The methods of its construction are specified. Investors may be able to invest in a stock market index by buying an index fund , which is structured as either a mutual fund or an exchange-traded fund , and "track" an index. The difference between an index fund's performance and
192-402: A weighted average of current and various lagged values of a random variable. The terminology weight function arises from mechanics : if one has a collection of n {\displaystyle n} objects on a lever , with weights w 1 , … , w n {\displaystyle w_{1},\ldots ,w_{n}} (where weight is now interpreted in
224-464: Is a capitalization-weighted index . Its record high is 4756,82 set on 23 May 2007. The following table shows the annual development of the BEL 20 Index, which was calculated back to 1990. The following 20 stocks make up the BEL 20 as of June 28 2024. Stock market index In finance , a stock index , or stock market index , is an index that measures the performance of a stock market , or of
256-407: Is defined as but given a weight function w : A → R + {\displaystyle w\colon A\to \mathbb {R} ^{+}} , the weighted sum or conical combination is defined as One common application of weighted sums arises in numerical integration . If B is a finite subset of A , one can replace the unweighted cardinality | B | of B by
288-410: Is sometimes referred to as a density . If f : Ω → R {\displaystyle f\colon \Omega \to \mathbb {R} } is a real -valued function , then the unweighted integral can be generalized to the weighted integral Note that one may need to require f {\displaystyle f} to be absolutely integrable with respect to
320-451: Is that trust in the corporate management, index criteria, fund or index manager, and securities regulator, can never be replaced by mechanical means, so " market transparency " and " disclosure " are the only long-term-effective paths to fair markets. From a financial perspective, it is not obvious whether ethical indices or ethical funds will out-perform their more conventional counterparts. Theory might suggest that returns would be lower since
352-619: The Calvert Social Index , Domini 400 Social Index , FTSE4Good Index , Dow Jones Sustainability Index , STOXX Global ESG Leaders Index, several Standard Ethics Aei indices, and the Wilderhill Clean Energy Index. Other ethical stock market indices may be based on diversity weighting (Fernholz, Garvy, and Hannon 1998). In 2010, the Organization of Islamic Cooperation announced the initiation of
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#1732780745826384-656: The MSCI World or the S&P Global 100 —includes stocks from all over the world, and satisfies investor demand for an index for broad global stocks. Regional indices that make up the MSCI World index, such as the MSCI Emerging Markets index, include stocks from countries with a similar level of economic development, which satisfies the investor demand for an index for emerging market stocks that may share similar economic fundamentals. The coverage of
416-396: The unweighted situation in which all elements have equal weight. One can then apply this weight to various concepts. If the function f : A → R {\displaystyle f\colon A\to \mathbb {R} } is a real -valued function , then the unweighted sum of f {\displaystyle f} on A {\displaystyle A}
448-583: The weighted cardinality If A is a finite non-empty set, one can replace the unweighted mean or average by the weighted mean or weighted average In this case only the relative weights are relevant. Weighted means are commonly used in statistics to compensate for the presence of bias . For a quantity f {\displaystyle f} measured multiple independent times f i {\displaystyle f_{i}} with variance σ i 2 {\displaystyle \sigma _{i}^{2}} ,
480-485: The S&P 500 and the S&P 500 Equal Weight each cover the same group of stocks, but the S&P 500 is weighted by market capitalization , while the S&P 500 Equal Weight places equal weight on each constituent. Some common index weighting methods are listed below. In practice, many indices will impose constraints, such as concentration limits, on these rules. Some indices, such as the S&P 500 Index, have multiple versions. These versions can differ based on how
512-506: The best estimate of the signal is obtained by averaging all the measurements with weight w i = 1 / σ i 2 {\textstyle w_{i}=1/{\sigma _{i}^{2}}} , and the resulting variance is smaller than each of the independent measurements σ 2 = 1 / ∑ i w i {\textstyle \sigma ^{2}=1/\sum _{i}w_{i}} . The maximum likelihood method weights
544-463: The continuous setting, a weight is a positive measure such as w ( x ) d x {\displaystyle w(x)\,dx} on some domain Ω {\displaystyle \Omega } , which is typically a subset of a Euclidean space R n {\displaystyle \mathbb {R} ^{n}} , for instance Ω {\displaystyle \Omega } could be an interval [
576-407: The difference between fit and data using the same weights w i {\displaystyle w_{i}} . The expected value of a random variable is the weighted average of the possible values it might take on, with the weights being the respective probabilities . More generally, the expected value of a function of a random variable is the probability-weighted average of the values
608-424: The discrete setting, a weight function w : A → R + {\displaystyle w\colon A\to \mathbb {R} ^{+}} is a positive function defined on a discrete set A {\displaystyle A} , which is typically finite or countable . The weight function w ( a ) := 1 {\displaystyle w(a):=1} corresponds to
640-626: The full capitalization, float-adjusted, and equal weight versions is in how index components are weighted. One argument for capitalization weighting is that investors must, in aggregate, hold a capitalization-weighted portfolio anyway. This then gives the average return for all investors; if some investors do worse, other investors must do better (excluding costs). Passive management is an investing strategy involving investing in index funds, which are structured as mutual funds or exchange-traded funds that track market indices. The SPIVA (S&P Indices vs. Active) annual "U.S. Scorecard", which measures
672-435: The function takes on for each possible value of the random variable. In regressions in which the dependent variable is assumed to be affected by both current and lagged (past) values of the independent variable , a distributed lag function is estimated, this function being a weighted average of the current and various lagged independent variable values. Similarly, a moving average model specifies an evolving variable as
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#1732780745826704-593: The index components are weighted and on how dividends are accounted. For example, there are three versions of the S&P 500 Index: price return, which only considers the price of the components, total return, which accounts for dividend reinvestment, and net total return, which accounts for dividend reinvestment after the deduction of a withholding tax . The Wilshire 4500 and Wilshire 5000 indices have five versions each: full capitalization total return, full capitalization price, float-adjusted total return, float-adjusted price, and equal weight. The difference between
736-429: The index, if any, is called tracking error . Stock market indices may be classified and segmented by the set of underlying stocks included in the index, sometimes referred to as the "coverage". The underlying stocks are typically grouped together based on their underlying economics or underlying investor demand that the index is seeking to represent or track. For example, a 'world' or 'global' stock market index—such as
768-512: The index. In addition, a candidate for inclusion must possess a free float market capitalisation (in Euros ) of at least 300000 times the price of the index on the last trading day of December. The minimum requirement for an existing constituent to remain in the index is a market cap of 200000 times the index value. At each annual review, the weights of companies in the index are capped at 15%, but range freely with share price subsequently. The BEL20
800-594: The investible universe is artificially reduced and with it portfolio efficiency. (It conflicts with the Capital Asset Pricing Model, see above.) On the other hand, companies with good social performances might be better run, have more committed workers and customers, and be less likely to suffer reputation damage from incidents (oil spillages, industrial tribunals, etc.) and this might result in lower share price volatility , although such features, at least in theory, will have already been factored into
832-403: The market price of the stock. The empirical evidence on the performance of ethical funds and of ethical firms versus their mainstream comparators is very mixed for both stock and debt markets. Weight function A weight function is a mathematical device used when performing a sum, integral, or average to give some elements more "weight" or influence on the result than other elements in
864-452: The performance of indices versus actively managed mutual funds, finds the vast majority of active management mutual funds underperform their benchmarks, such as the S&P 500 Index, after fees. Unlike a mutual fund, which is priced daily, an exchange-traded fund is priced continuously and is optionable . Several indices are based on ethical investing , and include only companies that meet certain ecological or social criteria, such as
896-429: The physical sense) and locations x 1 , … , x n {\displaystyle {\boldsymbol {x}}_{1},\dotsc ,{\boldsymbol {x}}_{n}} , then the lever will be in balance if the fulcrum of the lever is at the center of mass which is also the weighted average of the positions x i {\displaystyle {\boldsymbol {x}}_{i}} . In
928-410: The same set. The result of this application of a weight function is a weighted sum or weighted average . Weight functions occur frequently in statistics and analysis , and are closely related to the concept of a measure . Weight functions can be employed in both discrete and continuous settings. They can be used to construct systems of calculus called "weighted calculus" and "meta-calculus". In
960-430: The unweighted average by the weighted average If f : Ω → R {\displaystyle f\colon \Omega \to {\mathbb {R} }} and g : Ω → R {\displaystyle g\colon \Omega \to {\mathbb {R} }} are two functions, one can generalize the unweighted bilinear form to a weighted bilinear form See
992-417: The weight w ( x ) d x {\displaystyle w(x)\,dx} in order for this integral to be finite. If E is a subset of Ω {\displaystyle \Omega } , then the volume vol( E ) of E can be generalized to the weighted volume If Ω {\displaystyle \Omega } has finite non-zero weighted volume, then we can replace
BEL 20 - Misplaced Pages Continue
1024-594: Was removed following the takeover by Sanofi , only to be replaced mid June by arGEN-X [ nl ] . The composition of the BEL 20 index is reviewed annually based on closing prices on the last Friday in February. These changes are effective after the third Friday of March. In addition to meeting a set of criteria demanding a company be "representative of the Belgian equity market", at least 15% of its shares must be considered free float in order to qualify for
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