Use the stock move as the first signal
Premarket stock movement is often the cleanest available signal before the regular option market opens. The option quote may be stale, wide, or unavailable, but the stock move can still give you a scenario to model.
In OptionsPeek, enter the contract you care about, set the base stock price, and model the premarket move as a dollar or percent change.
Estimate before you place a limit order
The estimate is not a guarantee of the opening option price. It is a planning anchor. It can help you avoid placing a limit order that is wildly disconnected from the stock move you are seeing.
This matters most when you already own the contract and want to plan a sell order, or when you are watching a contract and want a first-pass idea of where it may open.
Review the result after the chain wakes up
Once regular trading starts, compare the estimate with the live bid/ask, volume, spread, and updated Greeks. A premarket estimate should become one input in the plan, not the whole plan.
If implied volatility reprices hard at the open, the live option value can differ from the estimate even when the stock move was directionally right.