Gordon Gekko kind of brought this up a while back, but the discussion turned mostly toward day trading.... Concerning swing trading only, if I had 100K account, and wanted to use 10K for each position, with 5% stop loss, that would only leave me with 10 possible positions at once, risking a total of 1/2% of my account per trade. If I use 2:1 margin, and still risk 10K on each position, with a 5% stop loss, that allows me to carry 20 positions at once, while keeping the total risk to 1/2% of my account per trade. Doesn't this use of margin mitigate most of the "beware of margin" mantras? Because I'm not increasing my risk per trade, I'm simply taking on more of the same risk. In the above example, using 5% stops on 10K positions in a 100K account, I'd have to be wrong 200 times to blow up. With that kind of room for error, I'd say carrying 20 positions at a time instead of 10 isn't that much riskier. Plus, if you have positive expectancy, the more positions you are able to take the better. Of course there's the issue of freak gaps. However, those usually happen as a result of company specific news, meaning it's unlikely multiple positions will experience freak gaps at once, blowing up my account. So while having more positions open at once would technically make me more vulnerable to freak gaps, it's unlikely that simultaneous gaps will happen, save a nuclear attack. Even then, in the event of some freak disaster, if all 20 of my 10K positions in my 100K (leveraged to 200K) account gapped down 50%, I would only be down to zero, with no debt. However, the odds of a portfolio of 20 stocks all gapping down 50% at once is so negligable it's not even worth considering. So, am I missing some subtle mathematical risk here? Or is taking on more swing positions in the above example using margin a good idea?