Kiwi

Yes, although Bohr worked with Rutherford to form their joint Bohr-Rutherford model of the atom this story placed them in contact while Bohr was still firmly at home. Their meeting late while Bohr was still a student was far to late in his training for such a simple question. I was wondering (my first degree was in Physics and Rutherford was by far our most famous physicist) so did some googling. One of the best pages I found was a discussion on the problem itself: Measuring height of building with barometer Text - Physics Forums Library This apparently may have been the origin of the story (Dr Alexander Calandra): ALEXANDER CALANDRA I liked the "original"(?) last paragraph and its indication of the time of the stories origin. Actually it is a much more satisfying final paragraph. At this point, I asked the student if he really did not know the conventional answer to this question. He admitted that he did, but said that he was fed up with high school and college instructors trying to teach him how to think, to use the "scientific method", and to explore the deep inner logic of the subject in a pedantic way, as is often done in the new mathematics, rather than teaching him the structure of the subject. With this in mind, he decided to revive scholasticism as an academic lark to challenge the Sputnik-panicked classrooms of America.

So true brownsfan. Few here know whether I trade or not ... and the only reason even they might have to believe me are the screams heard across the seas when I make a costly mistake. .

Its not so much a win 2000 to xp. More of a windows millenium and then fix it.

I'd have a go even though Thale's view may be different. Situations that squeeze shorts - or any situations that generate excess liquidity because traders abandon their positions only to have their original view confirmed later - will be generated by a combination of actions from a number of actors. Some of the actors will be deliberately predating (selling into buy stops say) but others will not. Examples in the not camp would be wise traders holding off buying for the next S&R once the market seems to lack strength, traders who simply were waiting for a bigger pullback, traders who were looking for more or a different confirmation/signal before entering, etc, etc. So the market just behaves like markets will in such a situation. So Leonardo's view is that the wise trader, familiar with how the market as a whole acts might have been holding back to see what would happen at X then they buy. No negative view of others implied ... they were just playing to their understanding. The danger of a predation view is two fold (imo): - you might be lead to expect actions from the market that don't happen because most or even major actors are not behaving with that motivation/strategy - you may add to your stress in trading because it adds to the "i was wrong" or "i was taken to the cleaners" or some other thinking that makes trading more difficult than it needs to be. Having typed that lot I wouldn't be at all surprised in TT's view was different (or that he found a different way to express it). Hey TT, that wasn't a system trading board was it?

Hopefully, even though this is off topic, my friend won't delete me This subject of "competition or not" has come up on many forums and I find myself swinging in my view. A very experienced trader sometime known as Leonardo but posting this time as TheRealThing said these two things which offer (I believe) a realistic view of what we are doing in the market (as less than Salomon Bros scale): "That doesn't mean that great money can't be consistently made from xxxxx trades. I do, because it is my niche. I know it is a niche, and respect that it is just a niche." which is key -- building and knowing ones skills in extracting profit from your niche business. He also said: "Trade the market in a way it allows you to profit consistently over time. The market does not care who profits from its actions. Those who consistently profit the greatest understand what is going on better than the other participants. You can choose to follow the market where it wants to go and obtain what you want." On markets to justify the post: I got my bias on HSI right yesterday (up) but my system only took one trade (down, lol) and took 54 points profit. There is no stress in a mechanical system when you accept both winning and losing.

Clearly you are either lucky or cherry picking your trades Thalestrader. Or is it that you have specialized in a behaviour that occurs in many markets and when it does entrains participants to a reasonably limited number of options?

Michael: you may want to define "accuracy." For example MP is very accurate in describing where the TPOs for a particular period fell. But it probably isn't accurate in the sense that you might mean - useful but not "accurate." What would it need to do for you to consider it accurate?

Thanks Tams. I was wondering. So, its just that the features similar to MP are currently free (I don't see any TPOs etc). I would expect that when they are mature and bug free that if they approach a full market profile feature set then they will be a charged extra - most developers want a premium for this feature set.

The most frequent reason for a big move in the US futures at night has nothing (zero) to do with who or what type of traders are involved. And the volume is low for the simple reason that most US market traders are asleep, eating, watching the box or hunting one. The big moves occur because the Asian and European markets make big moves and the US market, cute puppy's tail that it is, dutifully follows its new leaders. That is of course, imbalance or pressure. But it certainly isn't magic.

Hey tams. C is also similar to pascal (and don't forget modula). After assembler I programmed in Pascal and can assure you that it didn't help much with (lol) EASYlanguage. I think C is more like pascal (at least you can build good code with it because its rich enough). FWIW. I think AFL was written like EL (higgledy piggledy) but the writer sensibly realized he'd better follow a real language and thus followed C structures which is good because you can write code for Amibroker which you can then move to real C (Sierra Chart) with little effort. Interestingly the code I've seen/converted from egnigger is also very C like.

Interesting. I don't think Daniel had experience of trading. Unless you are the one in a million who are not stressed when money is at risk then your brain operates differently during (and at various times during) the trading process. Personally I have been coding the clearest elements of my discretionary trading to 1. take me out of the process for all sorts of reasons, 2. allow better testing to avoid the impact of cognitive distortions, and 3. permit me to trade more markets simultaneously and thus focus on the best setups/processes. This has been interesting and one element that is of interest is that I also don't believe that each mechanical edge lasts forever - the markets twist and turn. Longer term system developers try to adapt with atr measures etc. I am taking the other approach which I think is more appropriate to short term systems where the market participants care about specific numbers and movement numbers and will adapt key numbers over time as the markets twist. So real time is mechanical systems - mid term is discretionary/optimization based tuning - long term is system retirement and birth. So - systems don't last forever but who cares?

I'm with zdo. It depends: - what you are trading - what your entry strategy is - what moves you are trying to capture My personal approach is to test each exit separately. If you then find that the pf on a quick exit is 2+ with a 60% win and the pf on a trailing or trailing+tightening exit is 2+ with a 30-40% win you might choose to combine them to give a result that: - has an averaged profit factor - has a smoothed return (and thus all the resulting system stats). Or you might not find that. But only testing will tell. Generally I think the heuristic that the market rewards you for doing what is hard is true ... but ones personal psychology might combine with hard to generate unprofitable in some cases which could also argue for a staged exit.

I'm curious James. I always thought you were a market profile trader, and thus, fairly unconcerned about user to market speed issues. Where am I getting that wrong?

Unbundled is cheaper for HSI ... in fact I think its cheaper for everything in AsiaPac except yen denominated products.

I guess that means u won't be on chat mk. I figured out a way to resurrect that strategy ... not quite as good but tradable again.

You are correct about prices. Its a bit under a tick. Years ago I realized that you should think of 1 tick on the hsi as being equivalent of 1/5th of a tick on anything else ... so the range of each day and the sort of noisy spreads you get from time to time make more sense. So a "real" hsi tick is HKD250 not 50. Daily range isn't 330 to 500 ticks but 66 to 100 ticks. Spread is usually under 1 real tick and those big intraday jumps are not 30pts but 6 When you think of it like that HSI starts to look like a really nice, manageable market, right?

With IB (Interactive Brokers) you can trade the mini Nikkei on Osaka and the mini Nikkei on SGX (smaller) so they're pretty micro. But to get any more micro you need to go to bucket shops.

Yes. You use what Anthony calls ACSIL (Advanced Custom Study Interface and Language) which is a rich set of interfaces to a C++ compiler (the watcomm one is delivered built in with the program but some people prefer other compilers/development environments). You can then write whatever level of complexity you require to drive your trading program. Basically there are two ways to code for SC: - the worksheet approach which is more intuitive for non-programmers but not as rich or flexible - the ACSIL approach which will let you do anything but is more "advanced." For simpler strategies both will give the same result.

Amibroker has a language that has similar structure, syntax etc to C, C++, C# In fact it is close enough to Sierra Chart's dll interface (C, C++) that I was going to test with AB and move to SC. Its also a very fast backtesting platform. But AB is more about single timeframe testing than anything else and I don't trust its interface with Interactive Brokers. By contrast Sierra Chart is very good for multi-timeframe and for communicating information between charts - so it suits the style of what I know I can make work. Also SC has a robust trading interface with IB which I have used for hundreds, maybe thousands of trades so I know how to drive it and trust it with my money. Note: a lot of platforms are a lot like C in their underlying language (Amibroker, Sierra Chart, Ninja (I think) and ESignal; metatrader stuff has a similar structure too). They then add interfaces to their charting and order entry and monitoring. Much of the complexity and difference lies in this area ... but once you learn one then if you can make it do what you want it tends to be easiest to stick with it. Once you can do it then whether it is rich enough to handle what you want becomes a big issue. At the moment Sierra is relatively week on testing but very strong on real time. By mid next year I expect they'll be medium/strong on testing. At present Amibroker is excellent on testing but the real time interface feels very beta and lacks richness. Horses for courses. Tam is right about traders.com except that they tend to be doing "yet another indicator" and its very different to building a trading robot that you can trust to run in real time. For that I suspect Tradestation, Metatrader and Sierra Chart might be the more mature choices - but I don't have wide experience of other platforms (and my endorsement of Metatrader is not based on personal experience, just the number of people at FF doing stuff with it).

I know. us$10 per month. B'stards I guess it won't kill me but I always really like free.

Maxima, the trick for me is that I had already written the order entry fron't end while I was partially automating my day trading. Then, I started to use Amibroker (which I like) to test systems but ran into two issues: - I didn't want to use it live (I'd much rather trust SC for that) - Its hard to do multi-timeframe stuff with it but easy for me with SC So I had the choice of building on Amibroker and moving to SC or building a test harness on SC and doing the full development on SC (admin will have a test harness next year thats better than mine but I can get the key elements of multivariable testing that Amibroker gave me from my version). It seems that everything I look at is developed with some group of traders or some paradigm and none quite fit my internal model so whatever I do I'm going to have to build some of it myself. LOL. So I stick with the one I know really well --- better the devil etc.

I don't think the issue is so much Sierra Chart as what I'm doing. My model of the market is one that is easy to see by trained eye but difficult to clarify to the extent that I would like. However I now have two of my three models looking reasonable. One has a pf of 2 and a win rate under 50% on out of sample data. The second is over 3 with a 60% win rate out of sample. The third, which I left to last while I worked through the issues with the less promising options should hopefully eclipse the other two. I know SC rather well and doubt very much that I'd find any other platform easier (I did program a few earlier and periodically discuss strengths and weaknesses with friends who use them). On the issue of running a system 24x7 I wouldn't choose that - but not because you couldn't, more because, in my experience, the markets I am interested in all have times when their behaviour favours one strategy or another. For example, what trend trader would day trade 6E during the US morning if they had the choice of the less news shock prone European morning instead.

I bought a system called GSX in the early part of the decade. It was profitable then with zero interference. And it was still profitable last year with no interference. There is a newer slightly better version but the old one hasn't died.

I've just started moving towards intraday mechanical trading. I used to mechanically trade futures EOD but stopped some years back to take advantage of the much higher trade frequency in day trading. Money made = expectancy * amount risked * trades per year after all. But I have become bored with the process of semi-discretionary trading. So I am willing to sacrifice some quality for automation. The system will use Sierra Chart for I/O and decision making with Interactive Brokers TWS as the broker interface for trading futures and forex. It will be fully automated. Currently I am developing 3 systems on HSI and will then attempt to adapt them to other indexes and forex pairs. Some may not work on everything. One is countertrend; one is breakout; one is catching the rolling trends. My goal is to be a little fussy about which trades will be taken ... as the computer is not impatient about near misses. Currently it looks very promising but I would say these things: - no indicators are involved except a couple of mas used when defining trend although I just might try to develop a keltner based system as well. - because its price pattern based they are much more complex than your average system designers indicator related strategy - because they are complex there are a lot of variables (system designers are going "warning warning") -- but the underlying principles are those I've used for discretionary trading for years and the principles are simple ... just complex to program -- to my pleasant surprise the optimization has proved very robust (a wide range of stops, targets and trailing strategies have proved profitable and surfaces are quite flat). One thing that has kept surprising me is that things I thought when discretionary trading proved to be untrue under testing (once my software got complex enough to do the testing (1000s of lines of code)). It seems that I applied intuition to correct my rules so in some cases things are not mechanizable and in some cases a new rule can be developed.

There is more truth in a bucketshops (or anyones) price than the completely unreal volume. Why? Arbitrage. If the price is too far from the "agreed" price too often then a player can buy the low price and sell the high price and then close both positions when the prices get closer together. So price variations are short and calculated to make the profit gained higher than the risk of your customers arbing you.