A web page or webpage is a document or resource of information that is suitable for the World Wide Web and can be accessed through a web browser and displayed on a computer screen.
This information is usually in HTML or XHTML format, and may provide navigation to other web pages via hypertext links.
Web pages may be retrieved from a local computer or from a remote web server. The web server may restrict access only to a private network, e.g. a corporate intranet, or it may publish pages on the World Wide Web. Web pages are requested and served from web servers using Hypertext Transfer Protocol (HTTP).
Web pages may consist of files of static text stored within the web server's file system (static web pages), or the web server may construct the (X)HTML for each web page when it is requested by a browser (dynamic web pages). Client-side scripting can make web pages more responsive to user input once in the client browser.
Color, typography, illustration and interaction
Web pages usually include information as to the colors of text and backgrounds and very often also contain links to images and sometimes other media to be included in the final view.
Layout, typographic and color-scheme information is provided by Cascading Style Sheet (CSS) instructions, which can either be embedded in the HTML or can be provided by a separate file, which is referenced from within the HTML. The latter case is especially relevant where one lengthy stylesheet is relevant to a whole website: due to the way HTTP works, the browser will only download it once from the web server and use the cached copy for the whole site.
Images are stored on the web server as separate files, but again HTTP allows for the fact that once a web page is downloaded to a browser, it is quite likely that related files such as images and stylesheets will be requested as it is processed. An HTTP 1.1 web server will maintain a connection with the browser until all related resources have been requested and provided. Browsers usually render images along with the text and other material on the displayed web page.
Elements of a web page
A web page, as an information set, can contain numerous types of information, which is able to be seen, heard or interact by the end user:
Perceived (rendered) information:
* Textual information: with diverse render variations.
* Non-textual information:
o Static images on raster graphics, typically GIF, JPEG or PNG; or vector formats as SVG or Flash.
o Animated images typically Animated GIF and SVG, but also may be Flash, Shockwave, or Java applet.
o Audio, typically MIDI or WAV formats or Java applets.
o Video, WMV (Windows), RM (Real Media), FLV (Flash Video), MPG, MOV (Quicktime)
* Interactive information: more complex, glued to interface; see dynamic web page.
o For "on page" interaction:
+ Interactive text: see DHTML.
+ Interactive illustrations: ranging from "click to play" image to games, typically using script orchestration, Flash, Java applets, SVG, or Shockwave.
+ Buttons: forms providing alternative interface, typically for use with script orchestration and DHTML.
o For "between pages" interaction:
+ Hyperlinks: standard "change page" reactivity.
+ Forms: providing more interaction with the server and server-side databases.
Internal (hidden) information:
* Comments
* Metadata with semantic meta-information, Charset information, Document Type Definition (DTD), etc.
* Diagramation and style information: information about rendered items (like image size attributes) and visual specifications, as Cascading Style Sheets (CSS).
* Scripts, usually JavaScript, complement interactivity and functionality.
Note: on server-side the web page may also have "Processing Instruction Information Items".
The web page can also contain dynamically adapted information elements, dependent upon the rendering browser or end-user location (through the use of IP address tracking and/or "cookie" information).
From a more general/wide point of view, some information (grouped) elements, like a navigation bar, are uniform for all website pages, like a standard. These kind of "website standard information" are supplied by technologies like web template systems.
Kamis, 28 Mei 2009
Senin, 25 Mei 2009
Market participants
Unlike a stock market, where all participants have access to the same prices, the foreign exchange market is divided into levels of access. At the top is the inter-bank market, which is made up of the largest investment banking firms. Within the inter-bank market, spreads, which are the difference between the bid and ask prices, are razor sharp and usually unavailable, and not known to players outside the inner circle. The difference between the bid and ask prices widens (from 0-1 pip to 1-2 pips for some currencies such as the EUR). This is due to volume. If a trader can guarantee large numbers of transactions for large amounts, they can demand a smaller difference between the bid and ask price, which is referred to as a better spread. The levels of access that make up the foreign exchange market are determined by the size of the “line” (the amount of money with which they are trading). The top-tier inter-bank market accounts for 53% of all transactions. After that there are usually smaller investment banks, followed by large multi-national corporations (which need to hedge risk and pay employees in different countries), large hedge funds, and even some of the retail FX-metal market makers. According to Galati and Melvin, “Pension funds, insurance companies, mutual funds, and other institutional investors have played an increasingly important role in financial markets in general, and in FX markets in particular, since the early 2000s.” (2004) In addition, he notes, “Hedge funds have grown markedly over the 2001–2004 period in terms of both number and overall size” Central banks also participate in the foreign exchange market to align currencies to their economic needs.
Banks
The interbank market caters for both the majority of commercial turnover and large amounts of speculative trading every day. A large bank may trade billions of dollars daily. Some of this trading is undertaken on behalf of customers, but much is conducted by proprietary desks, trading for the bank's own account
Commercial companies
An important part of this market comes from the financial activities of companies seeking foreign exchange to pay for goods or services. Commercial companies often trade fairly small amounts compared to those of banks or speculators, and their trades often have little short term impact on market rates. Nevertheless, trade flows are an important factor in the long-term direction of a currency's exchange rate. Some multinational companies can have an unpredictable impact when very large positions are covered due to exposures that are not widely known by other market participants.
Central banks
National central banks play an important role in the foreign exchange markets. They try to control the money supply, inflation, and/or interest rates and often have official or unofficial target rates for their currencies. They can use their often substantial foreign exchange reserves to stabilize the market. Milton Friedman argued that the best stabilization strategy would be for central banks to buy when the exchange rate is too low, and to sell when the rate is too high—that is, to trade for a profit based on their more precise information. Nevertheless, the effectiveness of central bank "stabilizing speculation" is doubtful because central banks do not go bankrupt if they make large losses, like other traders would, and there is no convincing evidence that they do make a profit trading
Retail foreign exchange brokers
There are two types of retail brokers offering the opportunity for speculative trading: retail foreign exchange brokers and market makers. Retail traders (individuals) are a small fraction of this market and may only participate indirectly through brokers or banks. Retail brokers, while largely controlled and regulated by the CFTC and NFA might be subject to foreign exchange scams.[8][9] At present, the NFA and CFTC are imposing stricter requirements, particularly in relation to the amount of Net Capitalization required of its members. As a result many of the smaller, and perhaps questionable brokers are now gone. It is not widely understood that retail brokers and market makers typically trade against their clients and frequently take the other side of their trades. This can often create a potential conflict of interest and give rise to some of the unpleasant experiences some traders have had. A move toward NDD (No Dealing Desk) and STP (Straight Through Processing) has helped to resolve some of these concerns and restore trader confidence, but caution is still advised in ensuring that all is as it is presented
There is no unified or centrally cleared market for the majority of FX trades, and there is very little cross-border regulation. Due to the over-the-counter (OTC) nature of currency markets, there are rather a number of interconnected marketplaces, where different currencies instruments are traded. This implies that there is not a single exchange rate but rather a number of different rates (prices), depending on what bank or market maker is trading, and where it is. In practice the rates are often very close, otherwise they could be exploited by arbitrageurs instantaneously. Due to London's dominance in the market, a particular currency's quoted price is usually the London market price. A joint venture of the Chicago Mercantile Exchange and Reuters, called Fxmarketspace opened in 2007 and aspired but failed to the role of a central market clearing mechanism.
The main trading center is London, but New York, Tokyo, Hong Kong and Singapore are all important centers as well. Banks throughout the world participate. Currency trading happens continuously throughout the day; as the Asian trading session ends, the European session begins, followed by the North American session and then back to the Asian session, excluding weekends.
Fluctuations in exchange rates are usually caused by actual monetary flows as well as by expectations of changes in monetary flows caused by changes in gross domestic product (GDP) growth, inflation (purchasing power parity theory), interest rates (interest rate parity, Domestic Fisher effect, International Fisher effect), budget and trade deficits or surpluses, large cross-border M&A deals and other macroeconomic conditions. Major news is released publicly, often on scheduled dates, so many people have access to the same news at the same time. However, the large banks have an important advantage; they can see their customers' order flow.
Currencies are traded against one another. Each pair of currencies thus constitutes an individual product and is traditionally noted XXX/YYY, where YYY is the ISO 4217 international three-letter code of the currency into which the price of one unit of XXX is expressed (called base currency). For instance, EUR/USD is the price of the euro expressed in US dollars, as in 1 euro = 1.5465 dollar. Out of convention, the first currency in the pair, the base currency, was the stronger currency at the creation of the pair. The second currency, counter currency, was the weaker currency at the creation of the pair.
The factors affecting XXX will affect both XXX/YYY and XXX/ZZZ. This causes positive currency correlation between XXX/YYY and XXX/ZZZ.
On the spot market, according to the BIS study, the most heavily traded products were:
* EUR/USD: 27%
* USD/JPY: 13%
* GBP/USD (also called sterling or cable): 12%
and the US currency was involved in 86.3% of transactions, followed by the euro (37.0%), the yen (17.0%), and sterling (15.0%) (see table). Note that volume percentages should add up to 200%: 100% for all the sellers and 100% for all the buyers.
Trading in the euro has grown considerably since the currency's creation in January 1999, and how long the foreign exchange market will remain dollar-centered is open to debate. Until recently, trading the euro versus a non-European currency ZZZ would have usually involved two trades: EUR/USD and USD/ZZZ. The exception to this is EUR/JPY, which is an established traded currency pair in the interbank spot market. As the dollar's value has eroded during 2008, interest in using the euro as reference currency for prices in commodities (such as oil), as well as a larger component of foreign reserves by banks, has increased dramatically. Transactions in the currencies of commodity-producing countries, such as AUD, NZD, CAD, have also increased.
Banks
The interbank market caters for both the majority of commercial turnover and large amounts of speculative trading every day. A large bank may trade billions of dollars daily. Some of this trading is undertaken on behalf of customers, but much is conducted by proprietary desks, trading for the bank's own account
Commercial companies
An important part of this market comes from the financial activities of companies seeking foreign exchange to pay for goods or services. Commercial companies often trade fairly small amounts compared to those of banks or speculators, and their trades often have little short term impact on market rates. Nevertheless, trade flows are an important factor in the long-term direction of a currency's exchange rate. Some multinational companies can have an unpredictable impact when very large positions are covered due to exposures that are not widely known by other market participants.
Central banks
National central banks play an important role in the foreign exchange markets. They try to control the money supply, inflation, and/or interest rates and often have official or unofficial target rates for their currencies. They can use their often substantial foreign exchange reserves to stabilize the market. Milton Friedman argued that the best stabilization strategy would be for central banks to buy when the exchange rate is too low, and to sell when the rate is too high—that is, to trade for a profit based on their more precise information. Nevertheless, the effectiveness of central bank "stabilizing speculation" is doubtful because central banks do not go bankrupt if they make large losses, like other traders would, and there is no convincing evidence that they do make a profit trading
Retail foreign exchange brokers
There are two types of retail brokers offering the opportunity for speculative trading: retail foreign exchange brokers and market makers. Retail traders (individuals) are a small fraction of this market and may only participate indirectly through brokers or banks. Retail brokers, while largely controlled and regulated by the CFTC and NFA might be subject to foreign exchange scams.[8][9] At present, the NFA and CFTC are imposing stricter requirements, particularly in relation to the amount of Net Capitalization required of its members. As a result many of the smaller, and perhaps questionable brokers are now gone. It is not widely understood that retail brokers and market makers typically trade against their clients and frequently take the other side of their trades. This can often create a potential conflict of interest and give rise to some of the unpleasant experiences some traders have had. A move toward NDD (No Dealing Desk) and STP (Straight Through Processing) has helped to resolve some of these concerns and restore trader confidence, but caution is still advised in ensuring that all is as it is presented
There is no unified or centrally cleared market for the majority of FX trades, and there is very little cross-border regulation. Due to the over-the-counter (OTC) nature of currency markets, there are rather a number of interconnected marketplaces, where different currencies instruments are traded. This implies that there is not a single exchange rate but rather a number of different rates (prices), depending on what bank or market maker is trading, and where it is. In practice the rates are often very close, otherwise they could be exploited by arbitrageurs instantaneously. Due to London's dominance in the market, a particular currency's quoted price is usually the London market price. A joint venture of the Chicago Mercantile Exchange and Reuters, called Fxmarketspace opened in 2007 and aspired but failed to the role of a central market clearing mechanism.
The main trading center is London, but New York, Tokyo, Hong Kong and Singapore are all important centers as well. Banks throughout the world participate. Currency trading happens continuously throughout the day; as the Asian trading session ends, the European session begins, followed by the North American session and then back to the Asian session, excluding weekends.
Fluctuations in exchange rates are usually caused by actual monetary flows as well as by expectations of changes in monetary flows caused by changes in gross domestic product (GDP) growth, inflation (purchasing power parity theory), interest rates (interest rate parity, Domestic Fisher effect, International Fisher effect), budget and trade deficits or surpluses, large cross-border M&A deals and other macroeconomic conditions. Major news is released publicly, often on scheduled dates, so many people have access to the same news at the same time. However, the large banks have an important advantage; they can see their customers' order flow.
Currencies are traded against one another. Each pair of currencies thus constitutes an individual product and is traditionally noted XXX/YYY, where YYY is the ISO 4217 international three-letter code of the currency into which the price of one unit of XXX is expressed (called base currency). For instance, EUR/USD is the price of the euro expressed in US dollars, as in 1 euro = 1.5465 dollar. Out of convention, the first currency in the pair, the base currency, was the stronger currency at the creation of the pair. The second currency, counter currency, was the weaker currency at the creation of the pair.
The factors affecting XXX will affect both XXX/YYY and XXX/ZZZ. This causes positive currency correlation between XXX/YYY and XXX/ZZZ.
On the spot market, according to the BIS study, the most heavily traded products were:
* EUR/USD: 27%
* USD/JPY: 13%
* GBP/USD (also called sterling or cable): 12%
and the US currency was involved in 86.3% of transactions, followed by the euro (37.0%), the yen (17.0%), and sterling (15.0%) (see table). Note that volume percentages should add up to 200%: 100% for all the sellers and 100% for all the buyers.
Trading in the euro has grown considerably since the currency's creation in January 1999, and how long the foreign exchange market will remain dollar-centered is open to debate. Until recently, trading the euro versus a non-European currency ZZZ would have usually involved two trades: EUR/USD and USD/ZZZ. The exception to this is EUR/JPY, which is an established traded currency pair in the interbank spot market. As the dollar's value has eroded during 2008, interest in using the euro as reference currency for prices in commodities (such as oil), as well as a larger component of foreign reserves by banks, has increased dramatically. Transactions in the currencies of commodity-producing countries, such as AUD, NZD, CAD, have also increased.
FOREX
Foreign exchange market
Presently, the FX market is one of the largest and most liquid financial markets in the world, and includes trading between large banks, central banks, currency speculators, corporations, governments, and other institutions. The average daily volume in the global foreign exchange and related markets is continuously growing. Traditional daily turnover was reported to be over US$3.2 trillion in April 2007 by the Bank for International Settlements.[2] Since then, the market has continued to grow. According to Euromoney's annual FX Poll, volumes grew a further 41% between 2007 and 2008.[3]
The purpose of FX market is to facilitate trade and investment. The need for a foreign exchange market arises because of the presence of multifarious international currencies such as US Dollar, Pound Sterling, etc., and the need for trading in such currencies.
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