I am sure it happens as saw it happen, I was sitting in front of computerscreens at a trading desk of an American brokerage. Small brokerage have not much to lose. IB is not the average brokerage, so a bad example. And the main question is: How can you check for 100% that it does not happen to you? Sig gave a very detailed explanation. Bottom line is he confirms that there is no 100% certainty.
I am not interested in the expected value. If they copy me I would lose $1 million dollar, not the expected value of $1,000. That would be the reality. Your logic makes no sense. Chance is not 0.1%. If they are not stupid, they would first screen 12 million clients and keep maybe 0.01% that is interesting enough to be copied. So if you are in that small group chances to be copied are hugely higher than 1%. At 0.01% we speak about 1,200 people. And I am sure there are not 1,200 clients there that are interesting enough to be copied. Depending of the assumptions that are taken, you can proof anything. Telling that there is control is funny, as the people who are theoretically able to cheat have to control themselves and then confirm to you they don't cheat. It is like a bankrobber who tells that he checked himself, and he can confirm that he did not rob a bank. You cannot be involved and be judge/auditor at the same time. Audits have to be done by independent persons who have no relation at all with the audited persons/companies.
My trading strategy is very simple, any technical person in the brokerage firm can quickly understand it if he looks into the order entry.
That question can be asked to anybody, students ging for a good education, sportmen, businessmen... and all people trying to do something to improve/change their life. Did you ask that question already to yourself? Comparing to minimum wages or Wall Street Hedge Fund Managers makes no sense. Each person has abilities and disabilities. You should just ask the question: did I achieve the maximum I could achieve? For some the minimum wage would be the maximum they could achieve, while for others being aWall St hedge fund manager might be mediocre.
If you can't grasp the concept of expected value then you've got no business in finance my friend. This is basic basic stuff. And no, none of us believe that someone who doesn't grasp expected value and appears to have a difficult time even stringing together a coherent sentence "was sitting in front of computerscreens at a trading desk of an American brokerage." and saw this happen. No one can guarantee anything to you, we live in a world where there are literally millions of bad things that have a very small but non-zero chance of happening to you. This one ranks far below both the probability and severity of a lot of others, like being one of the 250,000 people struck by lightening each year for example. If you want to be terrified of each one of these, then you can be reduced to a blubbering heap in the middle of a secure room somewhere. If you want to ignore a million of them and fixate on one...at least admit that's not rational behavior. If you want to enjoy life to the fullest and live with no regrets, then obsessing on every conspiracy theory thing that "you can't guarantee 100% won't happen" probably isn't in the recipe for that. But hey, you can lead a horse to water and all that. If you want to live in paranoia there's really nothing the rest of us can do to stop you absent making an honest effort to point it out to you for your own good.
I use the concept of expected value in my trading. Using it to see how big the possibility is that you are at risk of being copied is irrelevant for trading. So maybe you should google again what the concept of expected value is used for in relation to your own trading. If you have to start picking on languages it only proofs that you have no real arguments and try to avoid the subject. I speak better English then you will speak my native language. You probably won't even reach the level of a six years old child. It is also strange that an owner (at least that's what you pretend) of a business that covers Canada and the US has so much time to post all over ET.
Trading is about accepting and limiting risk to the lowest level possible. Healthy paranoia is better then naivety. As naivety will destroy you too.
Let's just say I didn't learn about expected value from Google. If you'd like to stop by my office and talk business over a coffee once this COVID thing is over you've got an open invite, just IM me. Until then, please refrain from calling me a liar. Seems like a reasonable request, don't you think? Best of luck to you then.