Bid, ask & spread

The bid is what buyers offer. The ask is what sellers want.

At any moment, the bid is the highest price someone will pay and the ask is the lowest price someone will accept. These two numbers sit right next to each other on every quote screen.

What the order book looks like.

The ask side (red) stacks above. The bid side (green) stacks below. The gap between the best bid and best ask is the spread. Every market order walks into that gap.

This one is an animated diagram in the app. See it in Vero.

The space between them costs you money.

The spread is the difference between bid and ask. When you buy at market you pay the ask. When you sell at market you receive the bid. That gap is the immediate cost of entering any trade. On liquid names it's a penny. On thin names it can be dollars.