What is a good options spread?

It depends on the product, but spreads under a few percent of the mid are generally considered tight.

Should I use market orders?

Market orders can fill at the far side of a wide spread; limit orders near the mid are usually better.

Concept guide

The bid-ask spread is the difference between the highest price buyers will pay and the lowest price sellers will accept.

Concept

spread % = (ask - bid) / mid, where mid = (bid + ask) / 2

Trading at the mid is an assumption, not a right. Wide spreads mean you pay to get in and again to get out, which can erase a thin edge.

Spreads widen when volume and open interest are low, when expiration is far away, and around events when market makers step back.

What is a good options spread?: It depends on the product, but spreads under a few percent of the mid are generally considered tight.
Should I use market orders?: Market orders can fill at the far side of a wide spread; limit orders near the mid are usually better.