When you buy a call and a put, the total cost becomes your cost of the Strangle. But if the range is too large then the stock may not be able to move in that range. Then does Strangle make sense to the trader. There is a way out which is called playing on volatility. When volatility goes up the premiums of calls and puts go up. That is when you can book profits on long strangles. That is a way of trading volatility without worry too much about price.