Education

The Mistake of Ignoring the Best Bid and Ask

By Walid Mograbi · 2026-05-22 · 2 min read

The last trade print can distract beginners from the prices that actually shape the next executable decision.

Why this lesson matters

The last trade print can distract beginners from the prices that actually shape the next executable decision.

The core idea

• Best bid and ask anchor real execution cost.
• Last price is not enough on its own.
• Thin liquidity makes this mistake more expensive.

Practical example

A user can feel comfortable with the last trade while the actionable buy price is already meaningfully worse because the spread is wider than expected.

Common mistakes to avoid

• Reading last price only.
• Ignoring the spread.
• Assuming every quote is equally executable.

Quick checklist

• Best bid
• Best ask
• Spread
• Depth
• Order size

Key takeaway

A good lesson improves judgment, risk control, and execution discipline before it changes action.

Important caution

Real execution starts at the book, not at the headline number.

Further reading

• https://www.iex.io/products/equities/order-types
• https://academy.binance.com/en/articles/what-is-an-order-book-and-how-does-it-work