Reading a price chart: bars, candles, timeframes and volume

Wednesday 21 October 2026, 10:00 ET (21:00 ICT). On a 30-minute NQ chart the first half hour of the regular session (phiên chính, RTH, 09:30–16:00 ET) is one candle: open 29,874.00, close 29,890.25, a small green body on top of a long lower shadow. It looks calm.

Switch to 1-minute and the same half hour is thirty candles. NQ slid 103 points to 29,771.00 at 09:43:51 ET, then rallied 146.50 points to 29,917.50 by 09:49:50. Same trades, same 84,370 contracts. Which chart is telling the truth?

Both. A chart is a summary of trades, and every summary leaves something out. This lesson teaches you to read it and to know what it hides.

Key terms

Price chart (biểu đồ giá): trades drawn over time, price on the vertical axis Definition.

Bar or OHLC bar (thanh giá OHLC): one slice of time summarised by four prices: open (first trade), high, low and close (last trade) Definition.

Candle (nến): the same four prices drawn as a body (thân nến) from open to close, with wicks (râu nến) out to the high and low Definition.

Timeframe (khung thời gian): how much time each bar covers Definition.

Volume (khối lượng): contracts traded in a bar, drawn as a volume histogram (biểu đồ cột khối lượng) under the price chart Definition.

Terms you need: A tick (bước giá) is the smallest price step: 0.25 points on NQ, worth $5 per NQ contract and $0.50 per MNQ ($20 and $2 per full point; M0.05). Long (vị thế mua) profits when price rises and short (vị thế bán) when price falls; a stop (lệnh dừng lỗ) exits if price reaches your loss limit; bid (giá chào mua) and ask (giá chào bán) are the best waiting buy and sell prices (M0.01, M0.02).

Chart first: one tape, three charts

How it works

From trades to a bar

Every trade has a time, a price and a size. A bar keeps four prices and one total: the 09:30 ET 1-minute bar that morning kept open 29,874.00, high 29,913.25, low 29,873.50, close 29,884.25 and volume 7,411.

An OHLC bar is a line from low to high, with a tick left at the open and right at the close. A candle adds a body: green when the close is above the open, red when below.

Reading body and wicks

Take the 5-minute candle from 09:40 to 09:45 ET:

• open 29,882.50, high 29,882.50, low 29,771.00, close 29,819.75.
• Body: 29,882.50 − 29,819.75 = 62.75 points down, a red candle.
• Upper wick: none, because the open was the high.
• Lower wick: 29,819.75 − 29,771.00 = 48.75 points.

A wick records where price went and did not stay; it does not record why, or whether the high or the low came first.

Timeframes: the same trades, different bins

A timeframe is a bin size. Thirty 1-minute, six 5-minute and one 30-minute candle come from the same trades, so the first open, last close, high and low match in all three. A higher timeframe hides the order of events; a lower one shows the path and every wiggle. Traders often read context on a higher timeframe and timing on a lower one. ATAS X can also bin by volume, range or tick count (PLAT2.03).

Volume: when the trading happened

On 21 October 2026 the 30-minute volume bars of the regular session (09:30 to 16:00 ET) fell from 84,370 contracts in the first half hour to 14,088 at 14:00–14:30 ET, then rose to 46,532 at 15:00–15:30 ET (sessionContext in m0-09-rebin-tape.json). The opening half hour traded six times a quiet afternoon half hour.

That day illustrates the U-shape measured across 60 NQ sessions in our lab MeasuredNQ (M0.04), described in a public NQ practitioner study PlausibleOne trader's study (spikes at 08:30 and 10:00 ET), and documented in US stock and index-return literature pointers PlausibleOther market. One day illustrates the shape; the 60-session sample measures it.

Volume tells you how much traded, not who was right: every contract had a buyer and a seller.

Inside the candle: the footprint

A footprint (biểu đồ footprint) opens a candle into rows of prices and shows, at each price, the contracts traded at the bid (a seller hit a resting buy order) and at the ask (a buyer lifted a resting sell order) Definition. The side that crossed the spread is the aggressor (bên chủ động).

The 09:48 1-minute candle (1,754 contracts) is a small red candle. In 1-point rows its footprint shows the heaviest trading at 29,897 (109 at the bid, 104 at the ask) and 11 contracts at the top row, 29,905. The rows add back up to 1,754: the footprint is the candle, seen by price (M3.01).

Term you need: delta. Delta is ask volume minus bid volume. The 09:48 candle’s delta was −68. M3.04 covers it.

Why candle patterns are still worth knowing

Candle shapes have names: a doji has almost no body; a hammer has a small body near the top and a long lower wick; an engulfing candle’s body covers the previous one. They are shared vocabulary.

Myth / hypothesis: A hammer at the bottom of a drop signals a turn higher, and an engulfing candle signals a reversal Lore. The names describe a shape. Whether the shape predicts anything is a separate claim, and our lab has not measured it on NQ.

They are still useful: a long wick shows where price was rejected, where a stop on the wrong side is expensive, and a pattern name is a claim you can test against a baseline (EV1.04).

Worked example: what the body hides, long side

The 09:45 to 09:50 ET 5-minute candle on 21 October 2026: open 29,820.50, high 29,917.50, low 29,802.50, close 29,897.00, volume 13,050.

• Body: 76.50 points = 306 ticks = $1,530 per NQ contract ($153 per MNQ).
• Lower wick: 29,820.50 − 29,802.50 = 18.00 points.

Suppose, for the arithmetic only, a long of 1 NQ at the 09:45 open, 29,820.50, stop 10 points below at 29,810.50. The 1-minute chart shows the low of 29,802.50 printed at 09:45:12, 42 seconds before that minute’s high. The stop was hit first: 40 ticks × $5 = $200 lost before costs, and the rally happened without the position. The wick showed how far price went; only the lower timeframe showed when.

The mirror and the failure

Short side. A short from the open to the close of the red 09:40 candle is 62.75 points = 251 ticks = $1,255 per NQ. At 09:43:51 it was 111.50 points ahead; held to the close, it gave back 48.75, the length of the lower wick. For a short, the upper wick is risk taken and the lower wick is profit given back.

Failure. The 09:30 to 10:00 candle from the hook is a long-lower-wick candle (hammer-like, though with a 27.25-point upper wick alongside its 16.25-point body and 103-point lower wick). The next 30-minute candle closed lower, at 29,858.50, after trading down to 29,787.25; the regular session then closed at 29,997.75, above both (sessionContext in m0-09-rebin-tape.json). One day cannot confirm or refute a pattern, which is why grades come from tests, not examples.

Do it on the platform

You read charts in ATAS X and send orders in TopstepX on a second screen (PLAT2.08).

Prop-firm note. Loss limits count every tick of a wick, not just the close. Size from the stop distance on your holding timeframe; the Prop Firm course covers how a firm’s limits meet your stop.

Common mistakes

Common mistake: Treating a description as an edge. “The open traded six times the volume of 14:00” says when activity happens, not which way, and one day is not a base rate.

Drill: build a 10-minute candle

Merge the two 5-minute candles of 21 October 2026 from this lesson (09:40 and 09:45 ET) into one 10-minute candle: open, high, low, close, volume (13,759 + 13,050), body and both wicks.

What we don’t know yet

• Whether any candle pattern predicts NQ’s next move better than a random bar of the same size: not yet measured.

Recap

• A candle keeps four prices and one volume; the body runs open to close, the wicks reach the high and low.
• Every timeframe keeps the same first open, last close and extremes; higher timeframes hide the order of events.
• Volume shows when trading happened; intraday volatility is U-shaped in measured US data.
• A footprint splits one candle into prices with bid and ask volume that add up to the candle’s volume.
• Candle pattern names are vocabulary; as predictions they are graded Lore.

Further reading

• CME Group education: free courses from the exchange where NQ trades.
• Marshall, Young and Rose (2006), “Candlestick technical trading strategies: Can they create value for investors?”, Journal of Banking & Finance 30(8).
• Andersen and Bollerslev (1997), “Intraday periodicity and volatility persistence in financial markets”, Journal of Empirical Finance 4.
• Order Flow, Measured: All claims, claim MR-08 (NQ volume by time of day).
• Our lab: every NQ price and volume in this lesson was recomputed from the lab’s own ATAS X trade history for 21 October 2026.

Before this: M0.01. Next: M0.02 gives you the vocabulary (bid, ask, spread) that every footprint row uses.

Educational content only. Not financial advice. Futures trading involves substantial risk of loss. Not affiliated with Topstep; firm rules change; check the Topstep help center.