SFSigFinSignal Finance
Chart Literacy

2.1 Anatomy of Price

Understand the building blocks of every chart — how OHLC data is constructed, what candlesticks actually tell you, and which chart representation to use when.

Layer 2: Chart Literacy — Chapter 1 Goal: Understand the building blocks of every chart — how OHLC data is constructed, what candlesticks actually tell you, and which chart representation to use when.

The Core Idea

Every chart you'll ever look at is built from OHLC data — four price points per time period:

  • Open
  • High
  • Low
  • Close

Different chart types are just different ways of visualizing these four numbers. Once you understand what they represent, all chart types become readable.

OHLC Explained

For any time period (1 minute, 1 hour, 1 day, 1 week):

  • Open = the price of the first transaction in that period
  • High = the highest price traded during the period
  • Low = the lowest price traded during the period
  • Close = the price of the last transaction in that period

Example: AMD Daily Bar

Date: June 17, 2026
Open:  $198.20  ← first trade at 9:30 AM ET
High:  $202.50  ← highest price during the day
Low:   $197.10  ← lowest price during the day
Close: $201.80  ← last trade at 4:00 PM ET

This is one data point. A daily chart with 252 trading days = 252 of these points.

Candlestick Construction

Candlesticks visualize OHLC data in a way that makes the relationship between open and close immediately visible.

Anatomy of a Single Candle

       │  ← Upper wick (high)
       │
   ┌───┴───┐  ← Top of body (close if green, open if red)
   │       │
   │ BODY  │  ← Real body (open-to-close range)
   │       │
   └───┬───┘  ← Bottom of body (open if green, close if red)
       │
       │  ← Lower wick (low)

Color Coding

  • Green (or white/hollow): Close > Open → bullish, buyers won the period
  • Red (or black/filled): Close < Open → bearish, sellers won the period

The Wicks (Shadows)

  • Upper wick: distance from top of body to the high
  • Lower wick: distance from bottom of body to the low
  • Wicks show rejection — where price went but couldn't hold

Reading a Candle's "Story"

Each candle tells you what happened during its time period:

Big Green Body, Small Wicks

"Buyers controlled from open to close. Strong conviction."

Big Red Body, Small Wicks

"Sellers controlled from open to close. Strong conviction."

Small Body, Long Upper Wick

"Buyers pushed price up, but sellers slammed it back down. Bearish rejection."

Small Body, Long Lower Wick

"Sellers pushed price down, but buyers absorbed and pushed it back up. Bullish rejection."

Small Body, Wicks on Both Sides

"Indecision. Buyers and sellers fought, neither won. Often signals trend exhaustion."

Tiny or No Body, Long Wicks

A Doji. Maximum indecision. Especially significant at trend extremes.

Why Candlesticks Beat Bar Charts

Bar Chart (older Western format)

   ─ High
   │
 ──┤ Open (tick on left)
   ├── Close (tick on right)
   │
   ─ Low

Functionally identical to candlesticks but harder to read at a glance.

Why Candles Win

  • Body color is instantly visible (green/red)
  • Body size shows conviction strength
  • Wicks vs. body ratio is easier to assess
  • Pattern recognition is faster

99% of traders today use candlesticks. Bar charts are mostly legacy.

Other Chart Types

Line Chart

Just connects closing prices. Removes wicks and bodies.

When to use: Long-term trend visualization. Earnings/revenue overlays. Anything where intraday range doesn't matter.

Why it's limited: Hides volatility, rejection, intraday battle.

Mountain / Area Chart

Line chart with the area beneath shaded. Aesthetic, not analytical.

Heikin Ashi

Modified candlesticks that smooth out price action.

Formula:

HA_Close = (Open + High + Low + Close) / 4
HA_Open = (Previous HA_Open + Previous HA_Close) / 2
HA_High = max(High, HA_Open, HA_Close)
HA_Low = min(Low, HA_Open, HA_Close)

Result: Cleaner trends, less noise. Consecutive same-color candles signal sustained moves.

Trade-off: Lags real price. You can't read actual entry/exit prices off Heikin Ashi candles.

When to use: Trend identification on noisy charts. Visual confirmation.

Don't use for: Actual entry/exit decisions. The real price might be very different from what HA shows.

Renko

Bricks of fixed price increments. Time is removed entirely — a new brick only forms when price moves a set amount.

Use: Trend isolation in highly noisy markets.

Drawbacks: Loses timing, distorts S/R levels, lagging.

Point & Figure

Even older. Columns of Xs (up) and Os (down). Only registers significant moves.

Use: Long-term pattern recognition.

Reality: Niche. Most traders never need this.

Volume Bars (The Companion Chart)

Every candlestick chart should be accompanied by a volume histogram at the bottom.

What it shows

  • One bar per candle period
  • Height = total volume traded in that period
  • Often color-coded: green if close > open, red if close < open

Why this matters

We covered this in 1.2, but the visual integration matters:

  • Big green candle + big volume = real buying interest
  • Big green candle + low volume = weak rally, often fades

We'll go deep on volume reading in Chapter 2.9.

Timeframe and Candle Size

A single candle represents whatever timeframe you've selected:

  • 1-minute chart: each candle = 1 minute of trading
  • 5-minute chart: each candle = 5 minutes
  • Daily chart: each candle = 1 trading day
  • Weekly chart: each candle = 1 trading week (Monday open to Friday close)
  • Monthly chart: each candle = 1 trading month

Mental Model

A daily candle is just an aggregation of all the smaller candles within it. The daily high = the highest high of all the 5-minute candles that day. Same for low. Open = first 5-minute candle's open. Close = last 5-minute candle's close.

This is why "what timeframe should I use" matters so much (covered in 2.2).

Reading OHLC Numerically

Beyond visual, you can extract useful info from the raw numbers:

Range

Range = High − Low

Measures the day's volatility. Compare to historical average to assess if today was a "big" or "quiet" day.

Body Size

Body = |Close − Open|

Measures conviction. Big body = strong direction. Small body = indecision.

Upper Wick Size

Upper Wick = High − max(Open, Close)

Measures rejection from above. Big upper wick = sellers active up there.

Lower Wick Size

Lower Wick = min(Open, Close) − Low

Measures rejection from below. Big lower wick = buyers active down there.

Position Within Range

Position = (Close − Low) / (High − Low)
  • Near 1.0 = closed near the high (bullish)
  • Near 0.5 = closed mid-range (neutral)
  • Near 0.0 = closed near the low (bearish)

This is a quick way to gauge a candle's character without staring at it.

What Candlesticks DON'T Show

Important to remember:

  1. They don't show order flow. You can't tell from a green candle whether 1 trader bought $1M or 100 traders bought $10K each.

  2. They don't show level 2 dynamics. Hidden orders, dark pool prints, iceberg orders all happen "between" the candles.

  3. They don't capture the journey. A doji means open ≈ close, but the price might have gone $5 up and $5 down within the period — the candle just shows the endpoints.

  4. They don't differentiate types of volume. Algorithmic vs. retail vs. institutional all blend together.

This is why multi-timeframe analysis matters (Chapter 2.2) — to see both the forest (daily) and the trees (intraday).

Practical Setup for Your Charting

Default Setup Recommendations

For TradingView (free tier is fine):

  • Chart type: Candlesticks
  • Default timeframe: Daily (for swing trading)
  • Add: Volume histogram at bottom
  • Color scheme: Green/red (default works fine)
  • Background: Light or dark (preference)

For deeper analysis, you'll add indicators (Layer 3), but for now keep it clean.

Common Beginner Mistake

Stacking 12 indicators on a chart. This obscures the price action itself, which is the most important thing. Start with naked candlesticks + volume. Add things only when you have a specific question.

A Mental Model: Candles as Battles

Imagine each candle is a battle between buyers and sellers during a fixed time:

  • Open = where the fight started
  • High = furthest buyers pushed
  • Low = furthest sellers pushed
  • Close = where the fight ended

Then ask yourself for each candle:

  • Who won? (color of body)
  • How decisively? (size of body)
  • Was there a struggle? (wicks vs body)
  • Was there rejection? (which side has the bigger wick)

This framing makes every candle into a story. And strings of candles tell larger stories — which is what the rest of Layer 2 is about.

Practical Takeaways

  1. Every chart is just OHLC visualized. Once you grok this, all chart types become readable.

  2. Candlesticks are the standard for a reason. Use them by default.

  3. Wicks matter as much as bodies. Big wicks = rejection = important.

  4. Don't fall for Heikin Ashi or Renko as your primary chart. Smoothing introduces lag, and lag costs money.

  5. Always have volume bars below your price chart. Volume context turns ambiguous candles into clear signals.

  6. The simplest setup is the most powerful one. Candlesticks + volume. That's it for now.

Quick Self-Check

Before moving to 2.2, you should be able to answer:

  • What are the four numbers represented by OHLC?
  • How do you determine if a candle is bullish or bearish?
  • What does an upper wick mean? A lower wick?
  • What's the difference between body size and wick size, and what does each measure?
  • Why is Heikin Ashi misleading for entry/exit prices?
  • What does it mean if a candle "closes near its high"?
  • Why should volume always be displayed with price?

Next: 2.2 Timeframes