A price chart answers exactly one question: what did people actually pay, and when? Not what analysts predicted, not what the company is "worth" — what real buyers and real sellers agreed on, transaction by transaction, plotted left to right through time. Everything else in technical analysis is decoration on that record. This module makes sure the record itself is legible.
The two axes
Time runs left to right; price runs bottom to top. Simple — but the first habit of chart literacy lives here: always check both scales before reading anything. A chart that looks like a crash might span two hours or two decades; a "huge" move might be two percent on a zoomed-in scale. Serious charting also often uses a logarithmic price axis on long histories, so that a move from 10 to 20 (a double) takes the same vertical space as 100 to 200 (also a double). On a linear axis, recent prices visually dwarf the past for no informational reason.
The four numbers
Charts don't plot every transaction — they compress each period (a minute, a day, a week) into four numbers: the open (first trade of the period), the high (most anyone paid), the low (least anyone accepted), and the close (final trade). OHLC, in the trade's shorthand. A line chart keeps only the close and throws the rest away; bar and candlestick charts keep all four. The close gets special respect by convention — it's the price the market was willing to sleep on — but the high and low are where the day's actual battle lines were.
Hold on to the auction intuition (it becomes a whole course later): the high of a bar is where buying got shut off; the low is where selling got shut off. Four numbers per period is a remarkably efficient summary of a fight.
Timeframes: one market, many charts
The same market produces a different-looking chart for every compression you choose. A stock can be rising on the weekly chart, falling on the hourly, and churning sideways on the 1-minute — simultaneously, with no contradiction, the way a tide can come in while individual waves retreat. Confusion between timeframes is one of the most common beginner errors: a trader takes a signal from a 5-minute chart, then judges it against the daily and panics. The discipline, taught properly in the multi-timeframe course later in this track, starts with a habit you can adopt today: decide which timeframe you're reading before you read, and say it out loud in your description. "On the daily chart, this stock has been rising for three months" is a literate sentence. "It's going up" is not.
What a chart is not
A chart is a record, not an oracle. It cannot tell you what earnings will be, what the Fed will do, or what tomorrow's bar looks like. The honest claim of technical analysis — the one John Murphy's standard textbook builds from (in paraphrase; the book breakdown covers it) — is that market action reflects the sum of what all participants know, want, and fear, so studying that action is studying the crowd itself. Whether the crowd's past behavior predicts its future behavior is a real debate (Module 6 faces it squarely). What's not debatable is that you can't even join the argument until you can read the record fluently.
Assignment
Open any free charting site and pull up one stock or index. Find the four numbers for yesterday: open, high, low, close. Then switch the chart between daily, weekly, and 5-minute views and write one honest sentence describing each. Three sentences, three different true stories, one market — once that stops feeling strange, you've cleared the first rung.