Roll Down

Rolling down is an adjustment made to an existing options position: you buy back (or sell to close) the option you currently hold, and at the same moment sell (or buy) a new option on the same underlying stock and same expiration, but at a lower strike price. It is really two trades bundled into one action, and most broker platforms let you place it as a single "roll" order so both legs execute together instead of leaving you unhedged in between.

Traders roll down for different reasons depending on which side of the option they are on. A trader who sold a call option and watched the stock drop might roll the short call down to a lower strike to collect more premium, since a lower strike call is worth more when the stock has fallen. Someone holding a long put that has moved deep in-the-money (meaning the stock price is well below the strike, so the put has significant value) might roll it down to a lower strike to lock in some of that gain while still keeping a position open, freeing up capital in the process.

The nuance beginners miss is that rolling down changes your risk exposure, not just your price level. Moving a short call's strike lower means the stock has less room to rally before that call goes in-the-money against you, so the position gets riskier even though it brings in more premium. Rolling a put down usually reduces the option's remaining value and its sensitivity to further stock moves (its delta), so it can lock in profit but also caps how much more you can make if the stock keeps falling. It is not a magic fix for a losing trade; it is a trade-off between more premium or locked-in gains now versus a different risk profile going forward.

Rolling down is distinct from rolling out, which moves the expiration date further away without changing the strike, and from rolling down and out, which does both at once. Each version solves a different problem: strike adjustments deal with price level, expiration adjustments deal with time.