Reading a stock quote and Level 2 data

Why quotes matter

When you look up a stock, you're presented with a stream of numbers that describe its current trading activity. Learning how to read a quote is one of the most important foundational skills for investors and traders because it shows not only where a stock is trading, but also how buyers and sellers are behaving in real time.

Level 1: the basic stock quote

A Level 1 quote provides the essential information most investors need to monitor a stock.

• Last price: the price at which the most recent trade occurred. It tells you where the stock most recently changed hands, but it does not necessarily represent the price you would receive if you bought or sold immediately.
• Bid price: the highest price a buyer is currently willing to pay for a share. This represents current demand in the market.
• Ask price (or offer): the lowest price a seller is willing to accept for a share. This represents current supply in the market.

Bid and ask size

Alongside the bid and ask prices, you'll often see a size value indicating how many shares are available at those prices. For example:

• Bid: $49.95, size 500 shares.
• Ask: $50.00, size 800 shares.

Reading the example

This means buyers are bidding for 500 shares at $49.95, while sellers are offering 800 shares at $50.00.

Bid-ask spread

The difference between the bid and ask is known as the spread. Highly traded stocks may have spreads of only a few cents, while thinly traded stocks can have significantly wider spreads.

• Small spread = high liquidity.
• Wide spread = lower liquidity.
• Wider spreads generally increase trading costs.

Volume

Volume is the total number of shares traded during the current trading session. It helps answer an important question: is there significant participation behind today's price movement? For example:

• High volume often indicates strong market interest.
• Low volume may indicate weaker conviction behind a price move.
• Always compare today's volume to the stock's average daily volume to provide context.

Open, high, low and previous close

These numbers summarize the stock's activity throughout the trading day. Together, they help investors quickly understand the day's trading range and performance.

• Open: the first trade of the session.
• High: the highest price reached today.
• Low: the lowest price reached today.
• Previous close: the final price from the previous trading day.

Level 2: the order book

While Level 1 data shows only the best bid and best ask, Level 2 data reveals additional layers of supply and demand. It displays multiple price levels where buyers and sellers have placed orders, creating what's known as the order book. For example:

• Bids of 1,000 shares at $49.95, against asks of 800 shares at $50.00.
• Bids of 2,500 shares at $49.90, against asks of 1,200 shares at $50.05.
• Bids of 5,000 shares at $49.85, against asks of 3,000 shares at $50.10.

A deeper view

This deeper view allows traders to see where larger concentrations of orders exist.

What the order book can tell you

Level 2 data may provide clues about short-term market behavior. For example:

• Large buy orders can indicate strong demand.
• Large sell orders can suggest overhead supply.
• Thin order books can lead to greater volatility.
• Dense order books may slow price movement.

Context, not prediction

Level 2 should be treated as context rather than prediction. Large orders can be modified, split up, moved to other venues or cancelled instantly. Because of this, visible orders do not guarantee future price movement.

Market depth

The collection of buy and sell orders at different price levels is called market depth.

• A stock with deep market depth typically has significant liquidity, easier order execution, smaller spreads and lower price impact from large trades.
• Stocks with shallow market depth may experience larger price swings, wider spreads, greater slippage and more volatile trading conditions.

Time and sales (the tape)

The time and sales window, often called the tape, displays every completed trade as it occurs. Unlike the order book, which shows intentions to trade, time and sales shows trades that have actually occurred. Each trade record typically includes:

• Time of execution
• Trade price
• Number of shares traded

Reading the tape

Experienced traders use the tape to evaluate buying and selling pressure. Common observations include:

• Repeated large trades at the ask may indicate aggressive buying activity.
• Repeated large trades at the bid may signal aggressive selling pressure.
• Rising volume alongside rising prices can suggest strong momentum.
• Rising volume alongside falling prices can indicate increasing selling pressure.

Why the tape is trusted

Because trades represent actual transactions, many traders consider time and sales more reliable than displayed orders alone.

Putting it all together

A stock quote provides a snapshot of the market, while Level 2 data and time and sales reveal what is happening beneath the surface.

• Level 1 tells you the current market price and basic trading activity.
• Level 2 shows where buyers and sellers are positioned across multiple price levels.
• Time and sales shows the trades that are actually being executed.

Who needs what

For most long-term investors, Level 1 data is sufficient. However, active traders often combine Level 2 data, market depth and time and sales to gain additional insight into short-term supply, demand and trading behavior.