Trading Pair Palette
Market makers generally offer more pairs to trade than ECNs because they have the flexibility to bundle small orders into large ones, offset some in-house, and send the rest upstream into the Interbank or a connecting ECN liquidity provider. ECNs generally offer only pairs composed of the major currencies and perhaps a few others. Straight-through order processes make it impossible to bundle small orders large enough for the Interbank. Only market makers do this, and it is one reason minors and exotics are more dominant on their platforms. A palette of 15 or 16 pairs is more than enough to satisfy most traders.