...at any one given moment, if you did a scan, who has the most available possible offerings given the parameters of your scan?

alstrat91,

Depending on whether it's agencies, munis, or corporates you're looking for, either E*Trade or Zions Direct can be equivalent in terms of the inventory they offer, and both offer far more inventory, more easily accessed by small accounts and then acted upon, than any broker I'm aware of. Where you will see differences between the offering-lists of the two is in tiny lots held in-house. But if either is simply acting as agent, rather than principal, then both are quoting from the same network of underlying desks (which any other broker should be able to make available to its customers, but for reasons unknown to me, don't).

If you're a "whale", or merely buy your bonds in larger sizes, then there are plenty of bond boutiques with Bloomies that could put you into more inventory than ET or ZD. But for 99% of bond investors, ET or ZD is the place they should be.

Charlie