I kind of disagree with this idea. Unfortunately in trading there is a Murphy's law which states something along the lines of "The market will do what is least expected" In real life this means, the trades you have most confidence in will turn out to be duds and those you think are duds outperform. I've been trading for many moons and I can assure you of this, the markets leap all over the place and one moment 'x' is flavor of the week, thens it's 'y's turn. When you are selling a position thats when it begins a run up, when you buy it then runs down. One of the main reasons my trading makes bank for me is because like a few hardy souls on ET, we sit on positions for some days, weeks, months or sometimes years. Longer term gives more certainty. But initially when I place a trade with conviction, it goes against me, even after years of trading, getting my timing perfect just never seems to work out. So getting back to the crux of my suggestion, diversification is sometimes better over a larger number of positions than a small number of large positions.