Could be wrong but I believe by notional traider wanted to know how much actual currency is represented by "1 Lot" - typically $100,000, sometimes $10,000. At Dukascopy for example, buying "1" contract is $1,000,000, buying "0.1" is $100,000, etc. As for this "HFT" business, are you making markets i.e. placing your owns quotes directly into the order book? or perhaps statistical arbitrage (does your platform separate out those 17 liquidity sources and allow you to buy/sell in and out of each or does it simply show you the best bid/offer across the entire pool with the promise of best-execution)? If you're doing Latency stuff, not sure who you're actually doing it against if you're not directly connected to an exchange or bank and also figuring out how to turn quotes around at least 100 times quicker (0.4ms - still slow) even on a limited budget. I hear a lot of "HFT" stuff about trying to get 200 trades a minute out of a basket of 4 currencies. My ex writes market making models to help quote on over 4,000 instruments at a time - to me "HFT" is this type of activity spanning 1000s of instruments simultaneously, trying to get 4000 split-second quotes out the door and into order books. 40ms is enough time to send ONE message (ex.1, ex.2) holding 4000 instrument and pricing codes to a co-located server that executes them all - the 40ms is one thing - it's how they are being used that makes the difference.