How to Read Trading Volume Alongside Price

Volume and trading value

Volume is the quantity traded during a candle. On a BTCUSDT chart it is how many bitcoins changed hands; on a Samsung Electronics chart it is how many shares. Trading value counts the same trades in money, shown in USDT or won. When you compare coins with each other, or compare one asset's distant past with today, trading value is the better measure. The quantity of a coin priced at a few cents cannot be compared with that of a coin priced in the tens of thousands of dollars, and when one coin's price rises tenfold, the same amount of money buys a tenth of the quantity. With stocks, a split changes the share count itself, so the height of old bars depends on whether the tool has adjusted past volume for the split. Whether the bars under the chart show quantity or money also differs by tool, so check that first on any tool you have not used before. Misread the unit and a conclusion like "trading has dried up" can flip to its opposite.

Each exchange has its own volume

The volume on a chart counts only the trades on that exchange and that trading pair. The volume on a Binance BTCUSDT chart includes neither bitcoin trades on other exchanges nor trades in other pairs or futures on the same exchange. That is why the volume bars look different from exchange to exchange at the same moment, and why volume in a Korean exchange's won market can spike on different days from overseas exchanges. Local news may crowd only the won market, while a wave of liquidations on overseas futures shows up only faintly on a spot chart. Some services show volume combined across exchanges, but the figure depends on which exchanges they include. So the baseline rule is to compare volume only within the same exchange, the same pair and the same candle length, and when volume jumps on one exchange alone, first suspect something specific to that venue.

Moves with volume behind them, and moves without

If a candle with a big price move also had heavy volume, many participants actually traded at those prices. If price jumped sharply on light volume, the order book may simply have been thin, so a small amount of orders pushed the price. Sudden long wicks during quiet hours or in low-volume coins are typical cases. That is why a widely used interpretation gives more weight to a move of the same size when volume backs it. The order of checks is simple: first read the size of the move from the body and wicks, then compare that candle's volume with its recent normal level, then ask whether the time of day is usually quiet. A common mistake is to read a large bearish candle on heavy volume as "everyone sold"; it equally means someone bought that much. Still, having weight does not guarantee the move will continue in that direction.

Volume on breakouts

When volume rises well above normal on the candle that breaks through a resistance zone that has capped price several times, it means a lot of new trading took place at that level, so it is used as one piece of evidence that the breakout is real. The reading is that the sell orders sitting in the zone were absorbed and that buyers were still willing above it. Textbooks tell you to be more suspicious of breakouts that barely poke through without volume, but breakouts with volume also fall back into the range fairly often. When checking, look in turn at whether the breakout candle closed above the zone, whether the volume multiple is clearly above normal, and whether the following candles stay above the zone. There are exceptions: right after major news, volume rises across the whole market, so the breakout candle's volume is hard to call special. Volume shows the "weight" of a breakout, but it does not decide the outcome. How breakouts are defined and how people try to filter out false ones is covered separately in the Part 2 article on breakouts and false breakouts.

Climax volume and shrinking volume

A candle at the end of a long trend where volume several times the usual erupts all at once is called climax volume. It is read as the trace of late buyers piling in, or of stop-losses and liquidations pouring out together, and textbooks often show the trend stalling afterwards. But large volume also appears often in the middle of trends, so whether that candle really was the end can only be said after seeing that no further highs or lows followed. When price keeps rising while volume keeps shrinking, some read it as fading participation. Yet prices often climb a long way on shrinking volume, so this alone is not enough to call the end. Also, volume counted in coins shrinks as price rises even for the same amount of money, so in that case it is more accurate to check again with trading value.

How to measure a volume spike

Saying volume is "high" only means something once you decide what you are comparing it with. A common method is to divide the volume of the candle that just closed by the average volume of the 20 candles before it. This site's volume spike scanner calculates it that way, labelling 2x or more as an increase, 3x or more as a spike and 5x or more as a surge, and it leaves out the candle still in progress, whose volume has not finished filling up. Changing the number of candles in the average changes the yardstick: a short window reacts to the recent mood, a long one only catches large changes. Normal volume in crypto markets varies by hour and weekday, so on short candles even an ordinary candle that follows a quiet period can show a high multiple. The opposite also happens: if a big-volume candle already sits in the previous 20, it inflates the average and makes the next spike look small.

• Multiple = volume of the closed candle ÷ average of the previous 20 candles
• Example: average 100, this candle 350 → 3.5x
• Also check whether the whole market rose together
• A big candle already in the previous 20 shrinks the multiple

Cumulative volume indicators such as OBV

OBV (on-balance volume) is a running line that adds a candle's volume when the close is higher than the previous close, subtracts it when lower, and leaves it unchanged when equal. Its value depends on where you start adding, so you watch the direction of the line rather than the number itself. If price is flat but OBV is rising, some read it as trading being concentrated in the up candles. Keep in mind that OBV is a blunt rule that adds or subtracts a whole candle at a time. Even a tiny rise in the close adds that candle's entire volume, so a single big-volume candle can tilt the line for a long time. It is therefore safer to take a divergence between OBV and price as information about which candles the trading went into, not as a forecast in itself. Volume profile, by contrast, groups volume by price rather than by time; you can see it with the volume profile chart tool, and it is covered separately in the Part 3 article on volume profile and VWAP.

Inflated volume: wash trading

Volume counts real trades, but there is no guarantee every trade was between two different people. When one person or group buys and sells to itself to manufacture volume, it is called wash trading. It is used to lift an exchange's ranking or to make a coin look actively traded, and the smaller the exchange or the thinner the coin, the more reason to be suspicious. On pairs with zero trading fees, trading back and forth costs almost nothing, so volume can balloon. Clues people point to include volume that stays large and steady while price barely moves, trades of identical size repeating at short intervals, and heavy volume alongside a thin order book. These clues are circumstantial, not proof. Large volume alone does not prove genuine interest.

Common misconception: volume tells you the direction

"There was a lot of buying volume" is not an accurate phrase. A trade only happens when a buyer meets a seller, so the quantity bought always equals the quantity sold. What can be distinguished is which side executed immediately against orders resting in the book, that is, whether the incoming market order was a buy or a sell. Binance reports, for each candle, the amount filled by market buys, and the volume spike scanner's market-buy share is that amount divided by total volume. Even this share only shows which side was in more of a hurry; it does not tell you the next direction. If a large limit sell order absorbed all the eager buying in a candle, price may actually have been capped. The same holds when several candles in a row lean heavily one way: it is a record of past urgency. Volume measures the size of a move and how many took part; direction is still told by price.

What looks different in crypto and stocks

Crypto trades around the clock, so the volume bars run without breaks. Within the day, though, busy and quiet hours are distinct, and the shorter the candle, the more time of day shapes it. Stocks have set regular sessions: in Korea roughly 9:00 a.m. to 3:30 p.m., in the US 9:30 a.m. to 4:00 p.m. local time. Opening and closing auctions and institutional orders pile up near the open and the close, so heavy volume in those two stretches is the normal shape of the day, and a large early bar is not special by itself. News that breaks outside the session shows up all at once as a gap at the next open and heavy volume in the first candle. Korean stocks have a daily price limit of 30% up or down; when a stock is pinned at the limit, orders pile up without filling, so volume can actually print low. Large names such as Samsung Electronics or SK Hynix can also see extra volume from index rebalancing or futures and options expiry days, so check the calendar too.

• Crypto: 24 hours, with big differences in normal volume by hour
• Stocks: heavy volume near the open and the close is normal
• Korean stocks: a stock pinned at the price limit can show low volume
• US stocks: whether extended-hours trading is included differs by tool

Reading it on a live chart

The rightmost candle on a live chart has not finished. If an hourly candle started ten minutes ago, its volume holds only part of an hour's worth, so it naturally looks smaller than the candles before it. Reading that bar as "trading has dried up" is a mistake; and if a few big trades right after the open have already made the bar tall, it may end much taller or stay as it is. This is the same reason the site's spike scanner leaves the in-progress candle out of the multiple. Anything judged from a single candle's value, such as the volume multiple, OBV or the volume of a breakout candle, should in principle be checked after that candle closes. If you want a rough sense mid-candle, you can scale by the share of time elapsed, but trading is not spread evenly within a candle, so treat it only as a reference.

A practical checklist

Checking volume in this order avoids most of the common mistakes. If any item raises a flag, take what you read from volume one notch less seriously. Volume does not replace price action; it adds how many participants went along with what price already said.

• Confirm whether the bars show quantity or money, and which exchange and pair
• Confirm it is a closed candle, not the one in progress
• Compare against the recent normal level (e.g. the previous 20-candle average) as a multiple
• Check whether that hour or weekday is normally busy or quiet
• Check whether the whole market or the same sector rose together
• Check again which way price actually closed