Trading costs · Execution risk
Options Bid-Ask Spread: how quote gaps eat Premium
Commission is not the only cost. The wider the quote gap, the farther you must cross to buy and sell—handsome Premium can be cut by execution first.
Read one options quote
Suppose a Call shows Bid US$1.80, Ask US$2.20. Spread is US$0.40 per share; with multiplier 100, that is US$40 per contract of gap. Mid is US$2.00—only the midpoint, not a fill guarantee.
| Action | Likely price | Cash per contract |
|---|---|---|
| Sell immediately | Near Bid US$1.80 | ~US$180 received |
| Buy immediately | Near Ask US$2.20 | ~US$220 paid |
| Mid limit try | US$2.00 | May or may not fill |
Sell at Bid then buy back at Ask and you may lose US$40 before commissions. Against US$180 received, that is ~22.2% of income.
Why annualised numbers get overstated
Many calculators treat a screen quote as fillable Premium, then annualise. A more conservative approach uses the limit you would actually accept and includes open and possible close costs. Frequent rolling that crosses part of the spread each time can erode cash flow heavily.
If monthly headline Premium is US$200 but open+close costs average US$25 plus US$2 other fees, net is US$173—about 15.6% below the unadjusted yield figure.
High open interest ≠ easy fills now
Liquidity is not one field. Volume is today’s trades; open interest is outstanding contracts; spread shows best quote distance; depth shows size at levels. Expiry, strike, session, and volatility change all of them. Liquid stock does not make every option series liquid—far OTM/ITM, very short/long expiries, and event windows can widen quotes or jump fast.
Market vs limit orders
| Order | You control | You cannot guarantee |
|---|---|---|
| Market | Priority on execution | Final price; fast markets may slip |
| Limit | Only your price or better | A fill; price may leave you |
Limits do not erase liquidity risk—they refuse prices beyond your line. When you must exit urgently, fill certainty and price control rarely maximise together.
Checks before sending
- Multiply spread × 100 × contracts into dollars.
- Record Bid, Ask, Mid, Volume, and OI—not Last alone.
- Recheck quotes in regular hours; avoid stale prices.
- Estimate open, close, and roll costs together.
- With limits, accept that the order may not fill.
FAQ
Is Last the price I can trade now?
Not necessarily. Last is the most recent trade and may be stale; tradable range is current Bid/Ask and depth.
Does a tight spread mean safe?
No. A tight spread is one liquidity clue—not a substitute for depth, volatility, contract terms, and stock risk.
Are limits always better than markets?
No universal answer. Limits give price control but may not fill; markets seek execution but final price may surprise.
Official: FINRA on market liquidity. Wider spreads raise buy prices or lower sell prices; limits control price but not fills.
Verified: 11 Oct 2026. Broker order handling, fees, and quote displays differ—check official terms.