What the basic chart shows you

A stock chart plots the price of a company's shares over time. The horizontal axis (left to right) shows time — hours, days, weeks, or years depending on what you're looking at. The vertical axis (bottom to top) shows the stock price in dollars. A line connecting the prices tells you whether the stock went up or down during that period.

Most charts start with a date range selector at the top or bottom. You can zoom in to see just today's trading, or zoom out to see the last five years. The wider your view, the easier it is to spot long-term trends. The narrower your view, the easier it is to see small daily moves — but also to mistake normal wobbles for meaningful change.

The price shown is usually the closing price — what the stock sold for at the end of the trading day. Some charts also mark the opening price (where it started that day), the high (the highest price it hit), and the low (the lowest price it hit). These four numbers together are called the OHLC data.

Key Takeaways

  • Stock charts plot price over time on a grid, with dates running left to right and dollar amounts running bottom to top.
  • Candlestick charts show the open, high, low, and close price for each day or period, and the color tells you whether the price went up or down.
  • Volume bars below the price chart show how many shares traded each day — higher volume often means the price move was more significant.
  • Moving averages are lines overlaid on the price that smooth out daily noise and show the overall direction the stock is trending.
  • Support and resistance are price levels where the stock has repeatedly bounced up or down, and they can signal where a price might pause or reverse.

Reading a candlestick chart

A candlestick chart is the most common way to display stock data. Each candlestick represents one time period — usually one day, but it can be one hour, one week, or one month. The candlestick has a thick rectangular body and thin lines (called wicks or shadows) sticking out the top and bottom.

The body of the candlestick shows the opening and closing price. If the stock closed higher than it opened, the body is usually green (or white). If the stock closed lower than it opened, the body is usually red (or black). The top wick shows the highest price the stock reached that day. The bottom wick shows the lowest price it reached. So a candlestick with a long upper wick means the stock spiked up during the day but then fell back down by the close.

A candlestick with a small body and short wicks means the price barely moved. A candlestick with a large body and long wicks means the stock swung wildly. Neither pattern tells you what will happen next — they just show you what actually happened during that period.

What volume bars tell you

Below most price charts, you'll see a bar graph showing volume — the number of shares that traded each day. Taller bars mean more shares changed hands. Shorter bars mean fewer shares traded. Volume is colored to match the candlestick above it: green if the price went up that day, red if it went down.

High volume on an up day suggests that many investors agreed the stock was worth buying. High volume on a down day suggests that many investors agreed it was time to sell. Low volume on either kind of day suggests that the move happened with fewer traders involved, which some investors see as less meaningful.

Volume spikes — sudden tall bars after a stretch of shorter ones — often happen when news breaks about the company or the market. A volume spike doesn't predict what happens next, but it does signal that something caught investors' attention.

Moving averages and trend lines

A moving average is a line overlaid on the price chart that smooths out the daily ups and downs. The most common ones are the 50-day moving average and the 200-day moving average. The 50-day line averages the closing price from the last 50 trading days. The 200-day line averages the last 200 trading days. As new days pass, the oldest day drops off and a new one gets added.

Moving averages help you see the overall direction a stock is trending without getting distracted by daily noise. If the price is above the 50-day moving average, the stock is generally moving up in the short term. If the price dips below it, that can signal a slowdown. The 200-day average shows the longer-term trend — a stock above its 200-day line is in a longer uptrend.

When a shorter moving average (like the 50-day) crosses above a longer one (like the 200-day), some investors see that as a bullish signal. When it crosses below, they see it as bearish. These crossovers don't may provide anything will happen, but they're watched closely enough that they sometimes trigger buying or selling.

Support and resistance levels

Support is a price level where a stock has repeatedly bounced upward instead of falling further. Resistance is a price level where a stock has repeatedly stalled or reversed downward instead of climbing higher. You spot these by looking at the chart and noticing where the price has touched the same level multiple times without breaking through.

Support and resistance exist because of human psychology and trading patterns. When a stock falls to a price where it bounced before, investors who missed the last bounce often buy again, pushing the price back up. When a stock rises to a price where it stalled before, investors who sold at that level before often sell again, pushing the price back down.

If a stock breaks through a resistance level on high volume, that level often becomes new support below. If it breaks through support on high volume, that level often becomes new resistance above. These breakouts can signal the start of a bigger move, but they also fail sometimes — the stock breaks through and then reverses back.

How to spot trends and reversals

An uptrend is a series of higher highs and higher lows — each peak is taller than the last, and each valley is higher than the last. A downtrend is the opposite: lower highs and lower lows. A stock in an uptrend is generally moving in a bullish direction. A stock in a downtrend is moving in a bearish direction.

A reversal happens when a trend breaks. In an uptrend, a reversal might look like the stock failing to make a new high, then falling below the previous low. In a downtrend, a reversal might look like the stock failing to make a new low, then rising above the previous high. Reversals don't happen overnight — they usually take days or weeks to develop, and they often fail partway through.

Common reversal patterns include the head and shoulders (three peaks where the middle one is tallest), the double top (two peaks at roughly the same height), and the double bottom (two valleys at roughly the same height). These patterns appear often enough that traders watch for them, but they're not reliable predictors — a pattern that looks like a reversal can fail and the trend can continue.

Common mistakes when reading charts

The biggest mistake is seeing a pattern and assuming it predicts the future. Charts show you what happened, not what will happen. A stock that fell 20 percent last week might fall another 20 percent, or it might bounce back up 30 percent. The chart alone cannot tell you which.

Another common mistake is zooming in too far. If you look only at the last three days of trading, normal daily wobbles look like major moves. You lose perspective on whether the stock is actually trending up or down over weeks and months. Zoom out to at least a few months to see the real picture.

A third mistake is ignoring volume. A stock can move up or down on very little volume, which often means the move is fragile and likely to reverse. A move on high volume is more likely to stick. Always glance at the volume bars before deciding what a price move means.

Frequently Asked Questions

What does it mean when a stock price gaps up or down?

A gap happens when a stock opens at a price far above or below where it closed the previous day, leaving a blank space on the chart. This usually happens overnight when news breaks after the market closes. A gap up (opening much higher) often follows good news. A gap down (opening much lower) often follows bad news. Gaps sometimes fill later when the price moves back to close the gap, but not always.

How do I know if a chart is showing me the right time period?

There's no single "right" period — it depends on what you're trying to understand. If you're a day trader, you might look at hourly or 15-minute charts. If you're a long-term investor, you might look at weekly or monthly charts. Start with a one-year or five-year view to see the big picture, then zoom in if you want to understand recent moves.

What's the difference between a line chart and a candlestick chart?

A line chart connects only the closing prices, so you see one point per day. A candlestick chart shows the open, high, low, and close, so you see much more detail about what happened during each day. Candlestick charts take more practice to read but give you more information. Line charts are simpler but hide intraday moves.

Can I use charts to predict stock prices?

Charts show patterns and trends, but they don't predict the future. Many traders use chart patterns as one input among many — earnings reports, company news, economic data, and market conditions all matter too. Even professional traders who study charts constantly get predictions wrong. Never rely on a chart alone to make a buying or selling decision.

Why do different websites show slightly different charts for the same stock?

Different data providers sometimes use slightly different closing prices, especially for stocks that trade after regular market hours. The differences are usually tiny. More importantly, different websites let you overlay different indicators (moving averages, volume, etc.), so the same stock can look different depending on what you add to the chart. The underlying price data is the same.