Thanks for your input; but to be relevant, your items need to be quantified and supported by evidence, or else they are just expressing sentiment which may or may not be true. Unfortunately I don't have rigorous statistical data; but in my experience I get price improvements of ca. 90% of the bid/ask spread, which is corroborated by the recent study by professor Schwarz in Irvine. (Although I got ca. 50% of the bid/ask spread lately with some rather illiquid stocks, which is still much better than what my cost at IB would have been.) 1. I sometimes trade ca. 10% of ADTV, and I have not noticed any negative impact on price improvements or market impact. 2. I'm not sure what you want to say with your example - did you mean you refer to the commission broker of the zero commission broker with your example? The Schwartz study and my experience are the opposite. Yes sometimes I get filled close to the bid (sells) or ask (buys), but this is not the rule; and the price improvement seems to be better than with IB smart orders. On the other hand, the problem with limit orders as discussed earlier in this thread still applies: Most opposing retail orders are "caught" by internalizers or market makers off-exchange at $0.001 off the bid or ask, and will never or rarely be matched with my limit order. 3. I'm not sure what you mean by "difficult", and what you mean by "your quote". I think the order handling by any broker is highly regulated - they have to either fill it internally, or forward it to an exchange. However, I'm not sure what you mean, so I cannot speak to it.
%% 2] Sounds right, only for that wide bid \ask spread. NOT sure an ETF well known by trader could not get much better improvement , but i dont know that one\ so each to his or her own...................................................... Seldom is anything free, except IBKR has sent me some '' free'' calandars
Re-reading Astrot's comment, I think he meant the transaction volume of the retail trader, not the volume of the stock. If so, then what is the limit? I heard there is a regulatory limit of 390 orders per day (averaged over a month) for options, or else brokers will classify the traders as professional which comes with higher commissions and less advantageous order routing. I also heard that some brokers (TD Ameritrade) applied the same rule to equity trades, not only options. My understanding is that this is to protect the market makers from "toxic" order flow, in the sense of "toxic" = "more sophisticated than the average retail order flow", which might undercut the market makers' profits. The assumption here is that an order volume of > 390/day is an indication of a higher sophistication of the trader. On the other hand my understanding is also that brokers generally benefit from higher trading volume of their retail customers, as market makers and brokers on average make a slim profit on the trades (even after price improvements). My understanding is that the profit is shared with the brokers in form of PFOF (payments for order flow). The two aforementioned goals seem to be contradictory from the broker's perspective. Back to the question: What is the limit? Is there a limit for equities trades at all (other than TD Ameritrade [now Schwab])? Under what circumstances would a broker cut the customer off the commission-free trading (assuming it is a "soft" limit)? Do the characteristics of the orders play a role?
%% IT varies. I like to ask 2 or more people, qualified to answer, @ broker. Their rules could be stricter than exchange. IF those 2 ,conflict ask more people LOL SCHW would most likely give a written warning, but i consider even a written warning, a failure, on my part