Futures - Position Sizing and Time Frames. Very Important.

If you have a $15,000 account are are trading one unit of e-minis (margin about $5000 depending upon the broker), adding another unit when the trade is going your way, etc., then you should only do short-term trades, trades on which you have a very high probability of success. This means trades when you are very sure about the direction of the market, a bottom has been formed, and you are targeting a pre-set level. You get out at that level. These should be conservative trades.

The above trades are not double-down trades where you can possibly see the market going against your trade and see yourself doubling or tripling down. If the market can go against you, it probably WILL. With only three units to trade, you could get wiped out.

If you want to build a futures position for a big currency move (which may be a one to three month trade), you may build the position over a few days and average in at extremes. In such a case you need to have at least ten units worth of capital and build the position over weeks. I haven't yet learned to do this successfully.