Most brokers compare LPs on spreads and commission. Pretty often, that's the part just designed to look good.
Ask these instead:
1. Is your slippage symmetric? If price moves in my favour during that window, do I get it, or only when it moves against me?
2. Can I see my markouts? Your LP already watches them. You should too.
3. Did my limits hold in the last gold spike, or did they change in the middle of the move?
4. When were my NOP limits last checked against what my book looks like today?
5. What's your markup on swaps over the interbank rate, and is it the same for every client?
6. If your own prime pulls your credit line tomorrow, what happens to my open positions?
7. If my flow profile changes, will you tell me, or just move me to a different stream?
A good LP answers all seven without hesitation. If the answers come back vague, that tells you something too.
