I found margin lending very useful in creating more capital to diversify my portfolio. However there is greater risk that one must not loss sleep over. In my own opinion I wouldn't borrow more then about 30-40% of my portfolio value and invest in good solid companies. Also the money borrowed will have interest so obviously you want to outperform that. My current loan is at 9.35% so if I don't do better then that i'm going backwards. Also reseach margin calls and dont get caught by one. Would try and explain but my bed is calling me.