Ehhh... I route a lot of my orders to Citadel, Knight/Getco, etc and haven't noticed problems being subpennied. If you're sending orders to a broker that's using an algo that's getting gamed... stop routing there. Most subpennying is the larger market makers trading against retail flow - which you have no chance of interacting with anyway.
Are you adding or taking liquidity? Citadel, Knight/GETCO, and 3 other firms form the vast majority of "subpennying" in the market. If you're taking liquidity, you're just "robbing yourself" of the .0001/share
D) you'd be getting if you used some "discount" broker's "smart"
D) routing system. By the way, in doing this you are forgoing any price improvement you might otherwise have gotten from a hidden order on the exchange, which is at a minimum $.01 (that's 100 TIMES what you'd get if the order were internalized/sold to wholesalers for a "price improvement" to you of $.0001/share, which is by far the most common case).If you're adding liquidity on those routes, I'd be curious to hear your experiences. I once sent a lot of liq-adding orders to a Knight route (whether directly or not, I can't remember), and Knight complained to the broker about it; probably not coincidentally, the trades were profitable (for me, not for Knight). It was a funny conversation when the broker contacted me, because I was generating a lot of fees for the broker; the broker really didn't want me to stop the trading, yet they wanted me to say something to Knight about what I was doing, etc. I just gave up and routed everything to exchanges, which ended up working much better anyway.