First, options theory and options pricing are based on stock's volatility (implied/expected and historical), which reflect the chance of a stock staying within specific range. And it works pretty well probabilistically, meaning that you can set your iron condor width or probability of winning 70% of the time, and that's what happens 70% of the time. The other 30% of the time the stock indeed may move outside of your range, so there is no guarantee that it won't. Second, the benefit of trading iron condors is that you can play both sides. Let's say that using basic options/spread you can bet on a stock going up and pay 30 cents to make one dollar, or if you wanted to bet in opposite direction you could bet 30 cents to make one dollar when the stock goes down. But what if you don't know which direction the stock will move and wanted to bet in both directions? Well, then you'd spend 60 cents to make $1 (30 cents each direction), which would be quite expensive and you'd risk losing the whole 60 cents if the stock doesn't make a big move. But when you trade iron condors then you become the dealer and you sell one $1 spread for 30 cents to one guy who bets up, and another $1 spread to another guy who bets down, also for 30 cents. This way you'll collect 60 cents and let the other guys sweat over whether their 30 cent bets will work out. If one of them wins then you give the winner his 30 cents back, plus 30 cents you collected from the other guy, plus 40 cents of your own money. So you've lost only 40 cents, not much more than the other guy who lost 30 cents betting on the wrong direction. But whenever you win, you win 60 cents (30 cents from each loser), and if you manage to do this just 50% of the time then you own the casino (in this example). You can adjust the bets you're collecting from both sides, while probabilities of you or them winning will also change. But at least you have some control of your choices, while the rest is basic math.