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Marty, I can give you my experience. I've used all the Signal systems,
including Quotrek; the FM-PCMCIA card in a laptop slot; and the cable box.
Quotrek and the FM card use the same radio stations, so they have the same
speed. I loved the PCMCIA card - it was great for traveling, and in most
cities you could catch the loop in your hotel at night and get all caught up.
But there is definitely a timing difference. In "regular" markets, the FM
broadcasts will lag the actual floor by about 5 to 20 seconds. Sometimes
they lag less, for example, if the signal coming into the processor is (say)
the DJIA and then the DJIA is updated right then as the next tick, the lag
can be 1 or 2 seconds. In "fast" markets, the lag can be as long as 30 to 45
seconds. This is obviously a problem if you are day-trading the S&P or
Bonds. Additionally, with the FM there is a "loop" problem in that some
quotes just don't make it around at all, or on an at-all-timely basis. This
is the situation in, say, grain options beyond the lead month, or stock
options on thinly traded issues. The information comes into the Signal
computers, but it is not broadcast right away because the processors are
programmed to give priority to the S&P, Bonds, many indexes, and high-volume
stocks. Thus the $50 out-of-the-money Microsoft leap put you bought last
year, on which the open interest is 3 contracts, traded one today and will
never show up on your screen. With the cable, the loop is much larger
(factor of 10), so you will get more of that kind of information. Beyond the
lag and no-loop issues, FM is also a problem in that most programs, including
ones you yourself develop, use bar lengths in time increments, rather than
tick increments, so they are all off. If it's 3-minute bars, say, your
standard error of estimate can be 10% on average. So your 3-minute bar is
not the same as the 3-minute bar on that great system you bought that
backtests so well! The cable box, to which I have switched, is almost -
almost - market-speed. The lag on the S&P is one second or less in a slow
period, about 2 or 3 seconds in regular markets, and 5 seconds in fast
markets and right at the open. I am told that some services - such as
FutureSource - are even faster. Some have said BMI is faster, too. (I
simply don't want to go through the hassle of changing everything around for
a 2-second advantage; it takes me so long to dial the phone and give my
account number.) You can actually test your system; you can call any broker
that has a live "box" (a squawk box with voices from the floor - scary!) and
listen to the ticks being given orally, comparing them to your screen, maybe
with a friend to time the difference. You're probably tired of hearing me go
on about Walter Bressert, but his trading firm has as its "hold" background
on the telephone the S&P pit voices; you could call up there (312-263-1399)
and ask to be put on hold. I hope this answers your questions.
Good luck.
Larry
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