It means the order is first sent to a HFT firm. They can either fill or pass the order on. HFT firm pays the broker for this priviledge.
These firms like retail order flow because it’s generally uncorrelated with institutional flow. Also the chance of getting steamrolled by buying before the rest of the orders hit and depress the price is a lot smaller.
For 99% of retail investors free trades in exchange for possibly worse execution is a good deal.
For brokers that sell order flow, you will never see price improvement based on changes in market conditions (naturally) after you submit your order. For brokers that don't sell order flow, it is still possible that you would see post-submit price improvement.
This effectively means that after you submit your order, you will never see price improvement, if you use a broker that sells order flow. This harms retail investors that may not actively be thinking about this sort of price improvement, but would still matter to them in terms of aggregate transaction costs.
> price improvement based on changes in market conditions
I'm not sure what you mean by this. Do you submit orders and expect them to sit around for awhile waiting for the price to get better? What if it gets worse?
> after you submit your order, you will never see price improvement, if you use a broker that sells order flow
This is completely false. Wholesalers regularly give price improvement to internalized orders.
These firms like retail order flow because it’s generally uncorrelated with institutional flow. Also the chance of getting steamrolled by buying before the rest of the orders hit and depress the price is a lot smaller.
For 99% of retail investors free trades in exchange for possibly worse execution is a good deal.