To Anenome, there is a fee per trade (not per units of stock traded), several dollars, plus a commission of the entire amount of funds moved. Always. No matter if gain or loss. That is why if you trade but get less than around 30-40 per cent profit, you are below the bottom line and lose money even when it appears you gained money.
Next.
ToxicAssets asked why many people who defend HFT don’t engage in HFT. I already answered the question. I’ll say it again, YOU NEED TENS OF MILLIONS OF DOLLARS TO PLAY WITH OR YOU WILL LOSE MONEY! Don’t have it then don’'t do it. The risk is high because the computer is the one that makes errors and sometimes wrongly identifies when a trade is possible. In that case, you will lose lots of money because you had to invest lots of money to get any reasonable gain. Remember, you need millions of stocks, else penny per stock is nothing and exchange transaction fee + commission places you below the bottom line: exchange transaction fee + plus commision is not a few pennies.
They are beneficial if you actually have the resources to engage in them; otherwise, stick to regular stocks, because your effective demand (I want a helicopter, but I can’t pay for it, so I’m not on the demand curve for helicopters and can’t trade money for helicopters since I don’t have any money) is too low to enter the HFT market.
If you having nothing to give in exchange for something else in a trade, then of course you can’t trade and won’t benefit by trade, SINCE YOU ARE NOT IN FACT TRADING.
Like the old Soviet anecdote: the store has lobsters for 1 ruble, but they are very small, and other lobsters for 5 rubbles, but they are very large, so what should I choose! Oh, I can’t make up my mind! Now, if I actually had 5 rubles, I don’t even have 1 ruble …
Finally.
ToxicAssets seems to be entirely suffering from absence of training in and lack of understanding of the method of science. He or she seems to believe there is neither such thing as science no objective true, that every description of a dynamical system has some AGENDA. (This is easily shown to be nonsense: because the proposition “truth does not exist” is either true, in which case it is false, or false, in which case it is false. Proof by dilemma, the opposite proposition, “true does exist” is necessarily true. Thomas Aquinas … )
It’s a mathematical question of utility maximization, given the preferences of both parties. Science describes the behavior these people would have to follow to satsify THEIR OWN goals, WHATEVER THEY ARE. Observe. IT IS INVARIANT TO CHANGE OF PREFERENCES.
IF it is voluntary exchange of things, which is the case IF AND ONLY IF the two parties have opposite preferences OTHERWISE they would keep what they have, THEN it is preferred over the alternatives by the two parties, OTHERWISE they wouldn’t have done it. The preferences of the observer do not enter in the equation, which is an IF … THEN … proposition, which is true by proof by contradiction.
IF by hypothesis A = B, THEN AC = BC, BECAUSE C = C, OTHERWISE AC ~ BC, which would imply that C ~ C, which is a contradiction, or A ~ B, which is contrary to hypothesis. THEN … is an objective inference, necessarily true, because it is literally identical to the initial conditions.
In this case, the only initial conditions are that TWO PEOPLE HAVE DIFFERENT PREFERENCES AND MEET. Then objective inference, that they shall trade and be better off FROM THEIR OWN PERSPECTIVES, is identical to that premise, hence implied by it and true whenever the premise is true.
Therefore, as HFT is a kind of trade, so it BENEFICIAL FROM THE PERSPECTIVES OF THE PEOPLE WHO TAKE BOTH SIDES. As an observer, I merely describe the situation, my own preferences don’t enter in to the equation.
To show that what I said is not correct, you must falsify the premise and prove this “everyone’s preferences are identical.” In that case and only in that case trade is not beneficial every time from the perspectives of the people involved. But is this really the case?
This is as trivial as it get.
All science is objective, as is logic-mathematics, too, positive, instead of normative. There is no agenda, any more than the equations of special relativity describing identity of diagonals or rigid bars during coordinate shifts have any agenda or the mass of some sub-atomic particle being such and such is some agenda.