T2W Guide to Trading
ata Feeds
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Edited by Rognvald -
Last Updated:17th April 2004
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Editor's Message:
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Welcome to the Data Feeds Guide. We hope that this will be a valuable resource for both new & experienced traders alike. This is your guide & I am its editor.
The Guide is here to allow sharing of the wealth of information on data feeds owned collectively by T2W members with individual members in a permanent & readily accessible way when needed. It will link with the site's review sections & suppliers' websites. It will use pictures to demonstrate the points being made. The Guide will allow T2W members to use the knowledge of other members to help choose, try out, use & get the best from data feeds they may utilise in their trading careers. It will also allow them to pass on their knowledge to other members who can then benefit from it.
There will always be gaps in the Guide that need filling. So, if you have information relevant to this Guide & feel it would be helpful to our community, please add it to the threads.
Clearly there are members expert on what particular data feeds have to offer & on their various idiosyncrasies. Until now members’ expertise has been tapped on a fairly ad hoc basis. I hope this will change & that members will feel willing & able to put some of their special knowledge into the Guide in an appropriate form. If you have information relevant to this guide that you feel would be helpful to our community, please add it to the thread. I'll look at any suggestions made, discuss them with contributors & add them to the Guide as seems appropriate.
Lastly if you'd like to volunteer as a particular forum editor or as a Columnist please email us at at
[email protected] with a description of your trading experience and the reasons why you think you'd make a good editor.
Rognvald.
Data Feeds Forum Editor
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How does it work?
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- Each forum will have a guide which will act a digest of information concerning the subject of that forum
- The guide will always be the top thread in the forum
- Each guide will have an editor who's job it will be to update the guide
- Please contribute to the guide in any way you can. The editor will integrate your suggestions, feedback and text into the guide - whereupon your post will be removed.
- For a full description and to discuss the guides further please use this thread
The Other T2W Guides
Here is a list of links to all the guides that T2W runs.
T2W Software Guide
T2W Data Feeds Guide
T2W Options Guide
T2W Forex Guide
T2W First Steps Guide
T2W Techies Corner Guide
T2W Indices Guide
Data Feeds Guide Contents
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1.
The Guide
2.
FAQs
3.
Recommended Forum Topics
4.
Glossary
5.
Further Resources
a)
Related Links
b)
Recommended Reading
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1.1 Introduction
As Traders we all need reliable & accurate data to fuel the software package(s) we use to analyse the instruments we trade in. Whether we depend heavily on Technical Analysis or trade on price alone or by reference to fundamental analysis we need to have price & other data to analyse our chosen instruments on our software & then trade them.
The data must fit our chosen time frame. It may be that End of Day (EOD) data is what we need. It may be that we need Intraday data. Either way the data needs to cover quotes from the exchanges that the instruments we wish to trade are quoted on so that we can analyse their price & trade them.
It is essential that the data feed chosen fits with & is supported by the Charting software chosen. It is for example pointless to try to feed Intraday data into an EOD package & vice versa.
1.2 Global Market Data
There are over 180 financial data sources worldwide. These cover more than 1.5M instruments. There are financial markets worldwide. The data flow is enormous & complex.
1.3 Types of data, Origin, Flow & Speed
It may be simplistic & trite to say data flows constantly back & forth from its origin to its points of use as waves do from shore to shore but this is a fitting analogy.
1.3.1 Price, Volume, Market Breadth
Financial product exists in various hands & is traded in various markets Demand & supply vary. Suppliers provide price quotations to meet that demand. Product ownership is exchanged for money. The price & volume of transactions varies with the supply of & demand of product. The process repeats itself. It has associated data. This is what concerns this guide.
Types of Instruments on which this data is readily available
- Equities
- Derivatives
- Fixed Income
- Foreign Exchange
- Money Markets
- Commodities
- Energy
- Funds
Data Origins:
The exchanges e.g. Eurex (the market places) own data relating to transactions they facilitate. It is available to members & sold to quote vendors (QV) who either resell or package it for others to resell e.g. S & P Comstock. They collate data from many sources & resell to large institutional clients, online financial portals (e.g. Yahoo,) resellers (e.g. Updata) & individuals.
1.3.2 News, Comment, Research, Economic & Fundamental Data
Comprehensive global coverage comes from news agencies (e.g.Reuters). Often packaged with price data it is also sold separately. Detailed fundamental research data is available e.g. Standard & Poor’s Retail investor Services. Significant economic data comes from government agencies.
1.4 Data & Timeframes
The importance of immediacy of data access depends on the trading timeframe. Trades measured in weeks do not require the same immediacy as trades lasting minutes.
The data must fit the trading time frame & may be:
End of Day (EOD).
This consists of the opening, high, low & closing price along with volume traded for the day.
Or
Intra day (ID).
ID data may be streamed or available as snapshots. Both types are accessible in real time (RT) or delayed. Certain broker feeds provide what amounts to“virtual” RT streamed data. It is a fast moving series of sampled snapshots of what passes through the exchanges covered. It does not cover all transactions & there is debate over its suitability for analysis purposes.
1.5 Speed of access (Data Latency):
The importance of the delay (latency) from price quotation to transaction confirmation is proportional to trading timescale. The shorter the time frame, the less is latency tolerable due to its potentially adverse contribution to uncertainty & slippage.
Every processing & distribution system that data interacts with on its journey to & from a trader’s desk adds latency. Every system from the trade matching engine & CPU that the contract is traded on, the Exchange Quote systems, the Q Vs’ internal systems, the QV global distribution systems, -
any hardware or software in the distribution, access or processing systems at
any stage of the triple journey from exchange to trader, trader to exchange & exchange to trader – introduces latency. Depending on delivery systems used, data will have been through at least 10 computers before it reaches the trader. The return journey initiating a trade & ending with the trades matching engine will be similar as will the confirmation (fill) journey. Traders should know that the use of separate charting & dealing feeds places them between systems each having separate rules & latency. These advantages/disadvantages must be carefully weighed against trading needs
A trader making many intra day scalping transactions (say in index futures) with multiple contracts should, & is more likely to be, interested in how to minimise latency & spend money on it than someone trading small quantities of stocks over a time frame of weeks.
Data latency increases with number of systems & physical distance travelled. The lowest possible latency data feed would be that provided to a fictitious trader in an Exchange building trading on its internal market data system. This is not realistic or a possible scenario. It is likely that QV feeds will nearly always be slower than Direct Access (DA) but they should show every tick – which broker feeds may not.
Traders must consider their need for low latency data in setting up their systems & weigh its cost when budgeting the costs of doing business. There is more information in the data feed delivery modes section.
1.6 Data Depth (Price, Volume & Participant):
Exchange Data is not uniformly available at the same level of detail but a higher pricet secures more content.
1.6.1 Level 1 - Basic content
The minimum level of detail acceptable for analysis & trading is what is referred to as Level 1 - e.g London Stock Exchange Level 1 content includes:
- Opening price, mid, best bid and offer, trade high and low, mid price high and low
- Individual trades
- Closing prices
- Prices in real time
- Order book Volume Weighted Average Price (VWAP), all trades VWAP
- Cumulative volumes, uncrossing price and volume
- Daily Official List prices
1.6.2 Level 2 – Depth of Market & Market Maker content
e.g. London Stock Exchange Level II quote includes:
- the Market Maker ID (MMID) and time. Bid, bid size, ask, and ask size data display
- the highest bid or lowest ask quote (Inside Market).
- signifies the next best quote (1st Outer).
- the second best quote (2nd Outer).
- the third best quote (3rd Outer).
- other data.
1.7 Data access as part of the trading process:
Traders who wish to back test their trading systems will need a data base containing price data covering their chosen instruments over an appropriate historical time.
1.8 Data Feed Delivery Modes:
Data feeds normally contain all the exchange & news data transmitted by the vendor in a digitally coded form. There are widely differing modes of delivery.
1.8.1 Methods currently Available:
There are a number of data feed delivery methods available – some of those are only appropriate for historical EOD data, some for RT data. All will deliver data to fixed sites. Some methods already do, or soon will be able to deliver data reliably to mobile sites.
1.8.2 For Fixed Sites/Networks:
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(a) Direct feed using a leased high-speed dedicated telephone line. [/SIZE]
The user leases a dedicated high speed “always on” telephone line (e.g.a T1 type line) from his premises direct to a provider’s data distribution centre. Available bandwidth starts at 512Kbps. These lines are very reliable & as bandwidth is uncontended & switching is reduced to a minimum, are very fast. They are costly & not used by many private traders as they can only be justified by large turnover.
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(b) Via Internet[/SIZE]
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Internet Access Methods:[/SIZE]
(i) Wired Internet connections
These are either dial up using Plain Old Telephone Service (POTS), ISDN or BROADBAND (adsl/radsl). Any wired method may be used but each has its advantages & disadvantages.
POTS: – The main issues are the time taken to connect (dial up) to the internet, dropped connections & lack of a true always on connection. Bandwidth restrictions may be an issue for power users. Its cheap.
ISDN: -The main issue is call costs. A dual ISDN should be more than enough for all but the most demanding users but if traders regularly need to transfer large files this will take longer than by broadband.
BROADBAND: – the main issues so far are wired exchange availability in more rural areas, connection reliability & access methods. Costs have fallen rapidly with greater take up. Beware the non broadband "Broadband" offerings. If you are collecting data RT also beware of the limited downloaded bandwidth offerings now starting to appear. Consider whether you really need a static Internet Protocol (IP) address.
Common to all three is the latency that can often be introduced to streaming data by Internet switching, rather, than as is commonly supposed, by bandwidth limitations (the size of the pipe). Data may issue from a source 500 metres away but could have made a 25000 mile journey through numerous systems to get to your site. Some ISPs are now offering bandwidths of up to 2Mbps (download) at a premium price. It is unlikely that most traders will need this additional bandwidth solely for data feed purposes but service reliability guarantees that are absent with the basic offerings are usually incuded. Thes may well be worth the extra cost.
(ii) Fibre Optic Cable:
These Internet connections can give broadband performance equal to copper wired connections but are available only in cabled areas. There can be difficult technical issues with Internet connections via cable for those wishing to operate a home network.
(iii) Satellite Internet connection:
This allows broadband connection to the internet in areas not served by wire or cable. The bandwidth available is not so great as that on landline. Complex signals such as those generated by fast moving markets may be degraded by adverse weather conditions (rain fade). Additionally there is delay (over & above that normally experienced by internet feeds & execution platforms) of about 1 second built into this type of system due to the distance travelled by the signal from source to destination & back via geo stationary satellite. Intra day traders looking for profit in very short time frames will probably be adversely affected by this latency & could experience significantly increased slippage on fills. This problem may be lessened in future years with the deployment of Low Earth Orbit satellites (LEO).
(iv) Wireless Broadband:
In the next year or so a new method of broadband provision will arise - particularly in rural areas. This will facilitate data feed access for those areas not served by wired exchanges. It is likely to be cheaper then satellite internet access & will almost certainly have lower latency. It is known as
WiMax:
WiMax is an acronym for Worldwide Interoperability for Microwave Access. WiMax is a non-line-of-sight, point-to-multipoint broadband wireless access (BWA) technology. It is viewed as a cheaper alternative to digital subscriber lines & cable broadband access, because the installation costs of wireless infrastructure are minimal, when compared with the wired versions, which can involve laying cables.
The 802.16a standard, which covers the 2GHz to 11GHz bands makes possible so called Wireless Metropolitan Area Networks (WMANs). These provide up to 31 miles of linear service area range with shared data rates up to 70mbps. That is said to be enough bandwidth to simultaneously support more than 60 businesses with leased line - type telephone connectivity, & hundreds of homes with broadband - type connectivity using a single sector of a base station, with little to no rain fade. With standardization comes the ability to mass-produce products, so research & development costs decline along with manufacturing expenses. This should make it possible to achieve lower-cost services, which WiMax proponents say will make BWA feasible for mass deployment along with other methods. “The idea is to have optimal connectivity in the optimal medium wherever you are.”
The broadband fixed access method uses a version of WiMax known as 802.16d. A more advanced version called 802.16e is under development. This supports mobility & should allow laptops & Personal Digital Assistants (PDA) to connect to a WiMax antenna from a distance, like a mobile phone talking to its nearest base station.
Leading the way is Intel, which wants to integrate 802.16 standards into its Centrino mobile chip technology, hoping to pump prime the market. It hopes to deliver the first WiMax chips in the second half of 2004. These will be 802.16d standard for fixed antennae. Intel is working with equipment vendors & may co-operate with companies like Siemens Mobile to help with deployment. By December 2004 “WiMax Certified” seals of approval will start to appear on equipment & components.
WiMAX must deliver a well-priced product to end-users. “Cable & DSL economics are that the average user gets 1,500 to 2,000 megabytes per month at 500kbps speed for $50,” explains an Intel spokesman. “That works out to a $.025 per megabyte yield — for example, 20 e-mails would be around 3 cents.”
BT is currently (March 2004) testing fixed access WiMax in four rural parts of the United Kingdom. Customers receive broadband fixed access by attaching a receiver to their houses. Outdoor installations of WiMax antennas are expected in the first half of 2005, with indoor installations of WiMax antennas following in the second half. BT is also exploring WiMax to support high-speed mobile broadband. Devices that have WiMax chips using the portable 802.16e standard may be available as early as 2006.
When WiMax takes off it should be the saviour of the rural trader needing a Broadband data feed access. It will also allow mobile data transfer & trading anyware in range of a WiMax network.
(c) Broadcast Technology:
Direct Satellite feed from a QV:
These systems broadcast data that is received by a dish set up at the user’s site. Bandwidth can be high at up to 3x standard ADSL download speeds. Although the data is slowed by its journey to & from the satellite this is compensated for by the direct nature of the links thus avoiding internet switching delays. Also as a larger & contention free bandwidth is available less algorithmic compression is used on the data thus speeding processing. The data is processed by a satellite modem & fed into the user’s software applications. Weather issues such as rain fade can degrade signal quality & have an adverse affect on data transmission.
FM TV feed from QV:
Thes are transmitted discretely as part of the TV signal, received via a standard aerial & then processed by modem for use in suitable software. These links tend to lag in RT in busy markets due to bandwidth bottlenecks. Less commonly data can be received via analogue Teletext using a computer TV card. The Teletext signals can be pasted into any DDE compliant feed. As this data is delayed & limited in its coverage of instruments there is generally no problem with speed although signal quality can sometimes be an issue. These will be phased out in a few years as digital TV gradually replaces FM analogue. There is no present commercial indication of financial data feeds being piggybacked onto digital TV or radio signals although the technology should allow it.
(e) CD ROM:
Although not a "feed" as such it is worth mentioning here that historical data is available on CD & in some cases by download from specialist QV – it is most commonly EOD
1.8.3 For Mobile Sites/Networks:
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Only Via the Internet[/SIZE]
There are presently several methods of obtaining access to data feeds via the internet on a “mobile” basis. These are mostly in an early stage of development. None are yet consistently available geographically. Most are confined to limited areas. None are yet in general use by traders. Some can be unreliable & very expensive. This will change over time. Anyone requiring a truly mobile solution should investigate options very carefully after a thorough consideration of all the factors involved. As of March 2004 their practical usage is more for the future than the present except for the well heeled enthusiast.
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Access Methods:[/SIZE]
(i) GPRS card in a laptop*
Now a comparatively “ageing” technology – it is slow & for data streaming for trading can be very expensive as several “lines” need to be bonded together – Updata ran its TA package on this in a demo using an Orange PCI card & bonded channels for extra speed some time ago – this is possible if you are prepared for a huge telephone bill. There will be international "Roaming" problems
(ii) GPRS Mobile phone/PDA type device*:
The main general contender seem's to be esignal’s QuoTrek. There are some FX & spreadbet offerings but seem mostly confined to "alerts" rather than providing interactive use. There will be "Roaming" problems
(iii) Wireless Networking to broadband internet via Laptop:
This is available through a technology known as 802.11 (after the International Standard). It can be accessed commercially at "hotspots" from a wireless network enabled laptop in a “Café/Pub/Terminal” situation or using a home based or office wireless connection & only within a short distance of wireless access points. Interference in congested areas, security problems, competing standards & bandwidth limitations may be issues for traders relying on such systems at present.
(iv) Mobile Satellite Internet Connection*:
The data is broadcast & received on a satellite dish mounted on a vehicle. The resultant feed is connected a laptop. Self aligning satellite dishes with appropriate GPS software are available. This method is presently limited to USA for regulatory reasons but is believed to be technically possible in Europe. Latency, vehicle modification costs & vehicle security should be considered bfore adoption by the intending "roaming trader".
(v) Satellite phone, modem & laptop link*:
In theory available worldwide - (Trade on Everest?) - in practice bandwidth, signal quality, call costs & latency are severely limiting isues for RT use. EOD based trading is a possibility for the adventurous enthusiast.
(vi) “3G” Mobile phone, modem/pci card internet connection to laptop: using WCDMA - Wideband Code Division Multiple Access*:
WCDMA is an approved 3G wireless standard which uses one 5 MHz channel for both voice & data. It offers Internet connection at data speeds up to 2 Mbps. It works by converting speech & data into digital information, which is then transmitted as a radio signal over a wireless network. It uses a unique marker (spreading code) to distinguish each different call (rather than a circuit for each) & enables many more people to share the airwaves at the same time - without static, cross-talk or interference. It is a technology for wideband digital radio communications e.g. multimedia, video & other capacity-demanding applications. It has been selected for the third generation of mobile telephone systems in Europe, Japan & the United States.
WCDMA uses variable rate techniques in digital processing & it can achieve multi-rate transmissions. It has been adopted
virtually as a standard in Europe where there is a lack of any competing technologies. This is not the case elsewhere.
A Vodafone network card, with data transmission speeds rivalling those of wired Broadband Internet connections, will be rolled out in Germany, Italy, the Netherlands, Portugal, Spain, Sweden and the UK in spring 2004. "What it gives you is that it enables you to work 10 times faster than you're able to do at the moment" Vodafone spokesman Jon Earl said. The card, which is expected to cost around 359 euros in Germany on subsidized contracts and 1,000 euros un-subsidized, should enable business users to log in seamlessly to corporate networks
Vodafone's 3G network covers about 30 percent of the UK population& a smaller geograhic area of the country. It is for the time being the only company in Europe offering such a laptop card. It is the first product to integrate 2.5G & 3G technologies. The card can deliver transmission speeds of up to 75% of that of a standard wired broadband connection when in 3G coverage areas. When out of those areas, the data rate reverts to that of a GPRS network. Vodafone currently has 3G Capacity in London, along the M4 to Newbury & in cities such as Birmingham & Manchester. This card would enable mobile streamed data anywhere in the coverage area Significantly perhaps, Vodafone has selected Reuters to be its 3G news provider. Data transmission charges have not yet been announced.
(vii) WiMax technology
As mentioned above.
* A WISP will be needed to provide internet connectivity to these services
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Question 1: "How should I choose an End of Day feed?"
Answer: Read this guide carefully until you understand the issues & are sure that this is what you need. Do your homework, ask any question you want on these threads & make a decision. You can get a lot of help here by posting your question in a new "Datafeed" thread.
Question 2: "What sort of RT feed do I need?"
Answer 2: Read this guide carefully until you understand the issues & are sure that this is what you need. Do your homework, ask any question you want on these threads & make a decision. You can get a lot of help here by posting your question in a new "Datafeed" thread.
Question 3: "Will ABC feed give me xyz instruments and will it cost me more?"
Answer 3:
Look up the QV websites for what they supply using our links & if you have a problem ask here by posting your question in a new "Datafeed" thread.
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ADSL:
Asymmetric Digital Subscriber Line is a type of DSL. It works by splitting an existing telephone line signal into two (by frequency), one for voice & the other for data. ADSL technology can work at up to 8Mbps download. The most popular services in the UK at the moment are running at speeds of 512Kbps (approx. 9 times greater capacity than a dial up modem), although data transfer of up to 2Mbps can be obtained. Upload transfer rates are 256Kbps on all products & this is why it is "asymmetric", because the download speed is different to the upload speed. RADSL is a rate adaptive version that allows a subscriber further away from an exchange to have a rate adaptive service as the distance would prevent a full rate service.
Bandwidth:
a data transmission rate; the maximum amount of information (bit /second) that can be transmitted along a channel
Broadband:
A transmission medium that is able to support a wide range of frequencies, typically from audio up to video frequencies. It can carry multiple signals by dividing the total capacity of the medium into multiple, independent bandwidth channels, where each channel operates only on a specific range of frequencies.
Delayed:
Where a QV holds back intraday data for a period of time in a memory loop – often 15 minutes. The delay introduced reduces the value of the intraday data substantially. It is often possible to find free delayed intraday data for this reason.
Direct Access (DA):
Where a feed or a broker has a direct connection to the Exchange with nothing in between.
Fibre Optic Cable:
A cable made of optical fibres that can transmit large amounts of information at the speed of light
Geostationary:
Having a geosynchronous orbit such that the position in the orbit is fixed with respect to the earth - “a geostationary” satellite
GPS (Global Positioning System):
A system for determining postion on the Earth's surface by comparing radio signals from several satellites. The system consists of 24 satellites equipped with radio transmitters & atomic clocks. Depending on the user’s geographic location, the GPS receiver samples data from up to six satellites. It then calculates the time taken for each satellite signal to reach the GPS receiver, & from the difference in time of reception, determines location.
Inside Market:
Between the highest bid & the lowest ask prices made by market makers
ISDN:
Integrated Services Digital Network lines allow a single wire to carry digital (pulse coded modulation) network services & voice at the same time using separate frequencies. The basic ISDN consists of 2 x 64kbps channels
Latency:
In a network, latency, a synonym for delay, is an expression of how much time it takes for a packet of data to get from one designated point to another. In some usages latency is measured by sending a packet that is returned to the sender & the round-trip time is considered the latency.
Low Earth Orbit satellites (LEO):
A low-earth-orbit (LEO) satellite system employs a large fleet of "birds," each in a circular orbit at a constant altitude of a few hundred miles. The fleet is arranged in such a way that, from any point on the surface at any time, at least one satellite is on a line of sight. A well-designed LEO system makes it possible for anyone to access the Internet via wireless from any point on the planet. Unlike geostationary satellites they move in relation to points on earth.
Market Maker:
A "market maker" is a firm that stands ready to buy & sell a particular stock on a regular & continuous basis at a publicly quoted price.
Quote vendors (QV):
Organisations that sell or display exchange market data delayed or RT, mostly via the Internet.
Real time (RT):
In real time – as it happens
Roaming:
Using wireless telephone communications networks in other countries with the user’s standard access device – phone/pda/pci card. A premium is normally chargesd for this service. Not all devices are capable on all networks.
Snapshot:
A fixed view of the price movement up to the time it was taken
Streamed:
Data that flows in delayed or real time
Tick:
Each trade/quote that arrives on a data feed
Trade Matching Engine:
Software providing real time price distribution & order matching. Necessarily handling hundreds, if not thousands of orders per second.
Wireless Network enabled laptop:
A laptop with a wireless PCI card to allow communication with a wireless network. The card is a combination of modem/transmitter/receiver
WISP
Wireless Internet Service Provider
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RRP: {Price} - {Amazon/GI whichever is cheapest} (£{Amazon/GI Price - % Off)
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Editor's Note on Data feeds
The inclusion of any data feed (or means of accessing one) in this guide is no guarantee of its performance. This depends on many factors including the equipment used, the other software it is run with & the use it is put to. RT data feeds (especially mobile ones) are very complex products. They depend for proper performance on a chain of high technology systems across the Globe functioning as specified. Many factors affect their performance & the way data is displayed on a trading screen & there is much to consider before purchase. The technical issues are well beyond the scope of this guide. None of the data or any software sources listed here should be considered as totally reliable. The Editor of this thread does not advocate the purchase or use of specific feeds. This thread is a guide & should be treated as such. Intending purchasers are responsible for making their own detailed enquiries in relation to their specific trading needs. Classification of the feeds into nominal types is a matter of judgement by the Editor. Any statements made here should not be taken as authoritative statements of fact nor is any warranty made.
Rognvald
Data Feeds Forum Editor
