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[haystack] 25/6/2002 20:40

Here are a nice set of trade codes in sequence for TSCO today going up in odd twos.
A01VAFHF02
A01VAFHD02
A01VAFHB02
A01VAFH902
A01VAFH702
A01VAFH502

and another

4011EYU502
4011EYU302
4011EYU102
4011EYTZ02

showing Z going to 1 and the T clocking up to U

This looks pretty much like a sequence number and not a code. If you were thinking of designing a system to uniquely identify trades then I think you would come to the conclusion that the sequences should have no meaning of their own. They should only have a meaning when looked up on the LSE server. I can't believe that the designers of the computer system would have embeded anything in the code itself. There is no need to do this. If the number is mearly a look up reference then it makes the system more flexible. The data items being looked up via the sequence number can then be as rich in meaning as is needed and can me modified and added to later with the minimum of alteration. I think this is a dead end. How the different sequences are chosen is more of a problem. It may be that it changes after a certain number of trades on the LSE or it may be pseudo random.

[kayak] 25/6/2002 19:17

Think in terms of a base 36 sequence number... e.g. after 0000009 would come 000000A through 000000Z and then 0000010 etc. Well spotted about the odd/even business though.

[m.t.glass] 25/6/2002 18:26

The odds/evens thing applies to the 36 differs used in the eighth column Baz. The 16 differs A-F and 0-9 are in column one, apparently in random order.

Going now.

I am not an anorak
I am not an anorak
I am not an anorak

[bristolbaz] 25/6/2002 18:21

don't forget that A=10 and F=15

[m.t.glass] 25/6/2002 18:20

I'll go with zzaxx99:

"..I'm 100% convinced that this is a centrally-assigned unique identifier that has no useful meaning to anyone apart from the LSE's software..."

[jonc] 25/6/2002 18:11

MT,

I suppose anything is possible.

But as Bully said earlier if Paul phones the LSE they will tell him there is no significance in the codes for us mere mortals.

Cheers

JC

[m.t.glass] 25/6/2002 18:08

No it's not that. When they get to the end of the odd letters they then run through the odd numbers, then the even letters/numbers, and repeat.

But the trades listings are full of such batches with only one character differing. Just going back one page on BT.A (and that's enough for me now thanks..) look at 2001-2003, 2042-2045 (where the sequence is 5,7,9,B) and 2059-2061. Always using alternate sequence. Giving no more than 36 differs before some other column needs to change.

[m.t.glass] 25/6/2002 17:51

JonC - They may be using only the odd-numbered letters of the alphabet on odd-numbered dates?

[jonc] 25/6/2002 17:47

MT,

It tells me that L N and P are missing.

Now if you can find them you might be onto to something.

JC

[m.t.glass] 25/6/2002 17:06

Just to cause a bit of headscratching:

There are often batches of trades in which the variable elements are minimal; only one character differing in each ten-character set.

Eg: Go the top page of today's trades (25 June) in BT.A and look at AT trades numbered 2069-2072 timed at 16:27:30.

The first character is from the usual 16; the letters A-F and numbers 0-9 (randomly selected server? but in this case not changing). And the last two as usual are the year 02.

Only the last of the middle seven characters differs..

Thus:
2072.... 901XUK3Q02
2071.... 901XUK3O02
2070.... 901XUK3M02
2069.... 901XUK3K02

Uniqueness attributable to only one alphabetic character? What does that tell us?

;O)

PS: If I was able to pick that out of the first page I looked at, I presume there must be millions of such examples out there.

PPS: If these 'unique transaction identifiers' involve only 36 choices of character (26 letters and 10 numbers) in each of seven positions, I presume they are only used to distinguish between trades within a set period - and can be reused the next day, next week, next month, whatever. In which case does something within the code identify the time period in which it was used? (it might be a sequential rolling stream within one column - but the sequence need not be a standard numeric one). There aren't enough possible combinations to use for individual trades ad infinitum.

[paulismyname] 25/6/2002 16:44

Methinks I smell a rat. If one know the codes and could identify them with a mm then you could maybe identify the UK variant of "the Ax" on individual set stocks. Just in case pressure is put on you dailos I have copied and printed out your post

[zzaxx99] 25/6/2002 16:24

-- dailos,

Been there, done this - I've checked both stocks with small number of MMs - too many different codes to be accounted for by the MMs, and stocks with large number of MMs & trades - too few sequences to plausibly account for all the MMs.

I'm 100% convinced that this is a centrally-assigned unique identifier that has no useful meaning to anyone apart from the LSE's software.

[bullshare] 25/6/2002 16:11

dailos; to save you time and energy if you phone the London Stock Exchnage they will tell you the prefix are random. Been down this route many times myself, thought i had cracked it and the numbers then varied.

[dailos] 25/6/2002 16:10

I have edited my post with the codes to add further, it seems more than one code per MM, very similar though. Anyway enough on this subject for now, should have completed my research before getting all excited and posting! will keep you informed
d.

[kayak] 25/6/2002 15:50

dailos, or ask your friendly broker what the 3 digit code he sees is, then find your trade in the trade list and see if you can find it in the trade code.

[jonc] 25/6/2002 15:48

All you need do is look at the trades for a stock with two MMs.

If dailos is correct there should only be two separate codes.

JC

[dailos] 25/6/2002 15:43

Kayak
broker says it does?!

[kayak] 25/6/2002 15:41

dailos, MMs do have three digit codes, but they don't appear as part of the trade code.

[dailos] 25/6/2002 15:38

JonC
I'm not saying the broker has a code, the MM does so i am told. Your broker probably puts your order to an automated process and gets picked up by one of a number of MM.
Posted this after buying some BSY a while ago, did it on the phone through a broker, who, when it came up on my screen as filled, said " 648p been picked up by ?????????(MM name, cant remember) asked him how he knew which MM picked it up he replied " by the 3 digit code"
Either hes having a laugh or........

[paulismyname] 25/6/2002 15:28

You carry on dailos, am interested.

Paul

[dailos] 25/6/2002 15:20

OK
to wet your appetite........
Warburg 002
Winterflood 801
Merrills 686
Strauss T 725 (aus)
Jenkins 451
BZW 198 (i think)

Edit, am still gathering info on this, now understand Warburg has 002, 102, 302
WINS 701 801 901, will post further when i know (providing i dont get too much flak in the meantime!)

[jonc] 25/6/2002 15:01

Paul,

Ihave done several trades in the same stock with the same broker and the codes were not identical in fact they were very different.

JC

[kayak] 15/4/2002 21:26

Paulismyname: as everyone has said sadly the year number at the end is actually the most useful piece of information.

The first digit or letter identifies a sequence of numbers. There appear to be 16 sequences from which numbers are allocated (perhaps there are 16 servers receiving trades from the market). The digits after the first digit (apart from the last two which are the year) form the sequence number, again using both letters and digits. If you take all the trades with codes beginning with a given digit or letter, you will see that the sequence number increments with each successive trade, taken across the whole market chronologically. Not very useful.

[clem] 15/4/2002 21:01

Identity of the trading parties is ment to be assured. ie no one can figure it out, or thats the theory. Thats always been a market protocol as far as Im aware so it should be impossible to disentangle IMHO.