Another important rule for today
Never risk more than 2% per trade. This is the most common - and yet also the most violated - rule in trading and goes a long way toward explaining why most traders lose money. Trading books are littered with stories of traders losing one, two, even five years' worth of profits in a single trade gone terribly wrong. This is the primary reason why the 2% stop-loss rule can never be violated. No matter how certain the trader may be about a particular outcome, the market, as the well known economist John Maynard Keynes, said, 'can stay irrational far longer that you can remain solvent.'