The following are comments only targeted for people on the retail side: I have been trading with them fx for over 4 years now. Liquidity is sufficient for my needs (standard 3-5 million in the most liquid pairs at a time, but can be increased if care to trade larger size). The price feed is one of the best you can get on the retail side, I am not aware of any other brokers that could offer better services. Dukascopy comes maybe close in terms of price feed but I dont like their platform, settlement procedures, and API. Stay FAR AWAY from the general bucket shops, dont go with a broker who does charge commissions on trades as their interest is clearly aligned against you.
IB (Interactive brokers) is a ECN broker and as that the spread is variable depending from the market. IB charges commission on traded volume NOT via spread.
I second that, not sure my English is that bad that it could be interpreted that IB does not change commission. They do.
I got 2 euros of interest in my account . . . it's going to cost me $1.50 to turn that back into dollars. I have dollar as my base currency, why doesn't ib just turn that interest into dollars? That is an inconvenience.
Very simple, because non-base currency cash exposures are borne by you (arising most of the time from generated p&l, bond coupon receipts, accrued interest,...) and thus you are charged for the conversion. That is what I like about IB, they charge each investor/trader the amounts they are due, resulting from your own trading decisions, not more, not less. A better question to ask is why IB would not have a cut-off level within which they would simply convert small amounts of exposure to base currencies. Well, they do but they are very small (mostly rounding "errors" after you converted back to base currency).
I just tested IB forex on simulator. Commissions are an outrage. 226.8 to trade USD/JPY per side independent of trade size. I have a feeling this is 266.8 Yen and not 22.68 USD?