You hold a long TSLA $420 call with only a few days left. Instead of letting it expire, you roll it out: sell the old call to close and buy a new one with more time (and optionally a new strike). Move the sliders to see what you receive, what the new call costs, and the net debit or credit to make the trade.
Before and after the roll
Close (sell)
Old call · $420 strike · 5d left
You receive
$-
Per contract (x100)$-
→
Open (buy)
New call · $420 strike · 60d out
It costs
$-
Per contract (x100)$-
Net debit to roll
$-
Plain EnglishRolling is just closing one option and opening another in a single move. It usually buys you more time or a better strike, and it costs the difference between the two premiums- what the new call costs minus what you get back for the old one. It is not free, and it is not magic: if the new call is pricier than the old one you pay a net debit; if it is cheaper you take in a net credit.
Three things to know about rolling:
A roll is two trades at once. You sell (close) the option you already own and buy (open) a new one. Brokers package it as a single order, but under the hood it is still two legs.
You pay the difference in premium. The net cost is the new call's price minus what you collect for the old call. More time and a lower strike make the new call pricier (bigger debit); a higher strike or a cheaper new call can even hand you a credit.
Rolling buys time, not a guarantee. Extending expiration keeps the trade alive so your view has more room to play out, but it also means more premium at risk. Your loss on the new long call is still capped at what you pay for it.
Taxes are not shown here. Options and the underlying stock are taxed differently, and it depends on your holding period and account type. None of this is tax advice.