They are symmetric in the sense that you can both buy and sell options, so whatever payoff curve you get e.g., by buying an option (say unlimited downside and f

They are symmetric in the sense that you can both buy and sell options, so whatever payoff curve you get e.g., by buying an option (say unlimited downside and fixed upside) you can sell the same option to get the mirrored outcome (unlimited upside, fixed downside).