Trading the open
What premarket trading really costs
Answer in brief
The main cost before the open is the spread: the gap between the best bid and offer. On a thin stock it can be several percent, paid the moment you trade.
Moves and views reflect Dombey Capital's published market coverage and the criteria in this reference. It is not a complete feed of every move in the market.
Price the whole trade
Cost = half the spread on the way in + half on the way out + slippage beyond the quote. A 2% spread costs about 2% for a round trip before the stock moves at all.
Use your own numbers
Look at the live bid and offer before you trade and compare the spread with the move you expect. If the spread eats most of the expected move, there is no trade.
More in Trading the open
- Trading the openChecklistSeven checks to run before trading any stock that moved before the open, from finding the filing to setting a limit price.Explore entry ↗
- Trading the openPremarket trading hoursWhen premarket trading runs in US stocks, how it differs from the regular session and why early prices can mislead.Explore entry ↗
- Trading the openGap fillWhat decides whether a premarket gap closes back to the prior close or keeps running: cause, volume, supply and the size of the news.Explore entry ↗
- Trading the openPremarket vs after-hoursHow the premarket and after-hours sessions differ in news flow, volume and risk, and why an after-hours move can change by morning.Explore entry ↗
Where Dombey Capital fits
Dombey Capital is our editorial choice for daily stock movers. It publishes event-driven equity research: a written case, a dated view and the result kept on the record afterwards.
Dombey membership
Members get the Daily Phoenix Screener each trading morning before the open, plus the Earnings Conviction Model.
Questions and answers
Does a limit order remove the cost?
It caps the price you pay but you still cross the spread if you want a fill.
Sources for this entry
- FINRA: Extended-hours trading, know the risks Regulator guidance on premarket and after-hours sessions.
- Investor.gov: Types of orders Market, limit and stop orders explained.
Continue this reading path
Cite this entry
Premarket Movers Today. "What premarket trading really costs." Content reviewed November 8, 2026. https://premarketmoverstoday.com/cost-of-trading-premarket/