data vendor. It also allows multiple applications to access both real-time and historical data at the same time.

• Pal File Real Time, by Investment Engineering Corp. will generate a price text file and maintain it in real time. The text file contains Date, Time, Open, High, Low, Close for a specified chart and then posts updates to this file in real time. The file will have one line for each bar in your chart. The resulting ASCII file can easily be read into any other program such as Excel, Access, ++, etc. This allows the user to easily integrate the real-time datafeed into other programs.

Plan

Use a charting package with a server that can communicate to your applications via Windows DDE or OLE protocol. Several commercial products that have this capability include:

• Townsend Analytics Server

• Omega Research TradeStation

• DBC Signal for Windows and BMI for Windows

• ILX Systems Workstation

• Telekurs FINVEST Workstation

• Dow Jones Workstation

The receiving application (yours) needs to support "hot link" or "advisory" client DDE. Your receiving application can be either homebrew or a qualified commercial product, such as Microsoft Excel and The Math Works MATLAB.

To help you part of the way, some vendors provide software development kits. For example, the Market Data Interface Library (MDIL) from ILX allows programmers to build customized market data applications for the Internet. Likewise, North American Quotations also offers several products specifically for developers and webmasters.

Plan

Code your own datafeed server.

If you develop your own, you can build in lots of data queuing to ensure incoming data is never lost. You can time-stamp incoming packets as they are received, so the time of receipt is saved correctly even if the storage system gets behind. You can save data files in any format or combination of formats you want. You can communicate to other application software any way you want. You can communicate to other computers anyway you want. Lastly, you can build in all sorts of error trapping to let you know if anything is going wrong.

For example, one clever fellow wrote his own personal server by using a TV/ Teletext/video capture board to extract prices from several different TV broadcasts via

satellite in Europe. He then wrote a server that collects data from the Teletext pages and applies filtering to ensure the data is good. It then distributes prices as single items via DDE to MS Excel and has no performance problems. Data is saved as standard ASCII text files, which ultimately is processed by Omega Researchs Super-Charts® (Supercharts® is a registered trademark of Omega Research, Inc.) charting software.

Questions to Ask

Can the server communicate by DDE or OLE to other applications? Can other applications transmit data to the charting program?

Audio Commentary

You will probably gain more insight into what is going on the exchange floor from an audio service commentary (squawk box) than from any datafeed. With this service, you can hear a commentator describe the floors activities. He makes no mention of sales or closes, rather comments almost exclusively in bids and offers. For example, you might hear, "50 bid at 60, 50 bid at 60, 60 at 70, 65 at 75, 70 bid at 80, 65 bid at 70." The commentary also includes comments from time to time about volume and who is trading. For example, you might hear, "little action now," "50s trading," "100s trading," "only Is and 2s trading," "only occasional locals," "Merrill Lynch selling 100s," "outside paper coming in."

Experienced traders claim that an audiofeed helps them attain a "3-D" perspective of the markets activities. You can hear the outcry and emotional level rise and fall, and phones ringing in the background indicating new orders coming in. This feedback can certainly help you avoid trading in very fast and very slow markets, as both situations will likely produce bad fills from slippage.

In addition, the commentator will let you know who is driving the market, either the paper traders or the floor. You may wish to avoid trades when the floor is "running the stops" to clear out their books. For example, if the market has just made a new low and the commentator says, "There are no offers and the floor is in control," it is likely that you have just seen a retest of the low in which the floor did a run on stops. Price may likely rebound to the upside.

On the other hand, the markets high-strung tension can be contagious and stressful. It can also be humorous, as the commentators expletives are not deleted when matters seem to get out of control.

Question to Ask

Does the vendor offer audio commentary? If not, check out Intersats service (see Appendix for Web link).

Customer Support

Good customer support is essential. If your datafeed is acting suspiciously, you need quick, intelligent help to resolve the problem. After all, it is your money that is at risk in the market. There are far too many complaints in this area; problems regarding responsiveness, overcharging, technical competence, timely bug fixing, refunds-and the list goes on.

A typical complaint about responsiveness reads:

Their phone is busy 85 percent of the day and my faxes are not answered for two to three days if at all. I cannot count how many times they have promised to return a call and not done so.

Another complaint said the vendor:

. . . seems to have plenty of people sitting idle in their offices. You should have seen the eyes of their salesman when I explained that I needed more than 10,000 ticks storage-they probably thought I was some nut trying to bad-mouth their product.

In complete contrast, some vendors give impeccable service. For example, heres one compliment heard on the Internet:

FutureSource (in London anyway) provides excellent backup. If I ever miss data they usually send it round on disk by courier. They have also sent me historical data if I start looking at a new market and havent previously been collecting data for that symbol.

Before packing up your bags and moving to London, consider that support staffs of most vendors will provide correct answers, albeit, at times, not without a little extra effort on your part. You may have to insist on speaking to a supervisor or manager if the person on the other end of the phone cannot help you. They are more knowledgeable and are responsible for making things happen.

Beware of "Free Trial" offers, as some vendors have a different interpretation as to the meaning of "free." For example, one respondent complained that a vendor

. . . advertised a 30-day free trial. But I discovered its only free if you do not continue with the service. Otherwise they charge you for the first 30 days.

Read your service contract carefully. One customer complained,

They get you to sign a 1 year contract without making it clear that (1) they will not let you out of the contract for any reason and (2) they wont even let you