Tape reading
Tape reading is the practice of reading the live stream of executed trades, their price, size, side and pace, usually together with the order book, to judge who is aggressive, whether prices are being accepted and when that behavior changes. It predates charts: Richard D. Wyckoff published 'Studies in Tape Reading' in 1910 under the pseudonym Rollo Tape.
Senzoukria · Glossary · Updated September 2026
What a tape reader watches
- Side: whether trades hit the bid or lift the offer, and whether one side dominates for a while.
- Size: whether the flow is made of a few large prints or many small ones, and whether sizes repeat.
- Pace: how fast trades print compared with the recent normal; acceleration often precedes or accompanies a move.
- Result: whether price actually moves after the aggression. Heavy selling into a bid that does not drop is a different message from the same selling pushing price down.
- Location: what happens at levels that matter, such as the prior high, the value area edges or a visible wall on the DOM.
A worked example
Price reaches a bid of 150 contracts at 5,000.00. For two minutes, the tape shows a stream of sell prints at 5,000.00, many of them merged lines of several trades, while the displayed bid keeps showing roughly 150 contracts. Price does not trade lower. Then a single buy of 300 contracts prints at 5,000.25, the offer above is lifted and the next prints come in at 5,000.50 and 5,000.75. The tape has shown absorption at the bid, then initiative buying: sellers spent their orders without result, and buyers took the other side. The same sequence would be read differently if the bid had shrunk as the sells printed.
Traps of reading prints
- Many platforms merge trades that share a price and side within a short window; a large line can be one order or dozens.
- Aggregated trade formats on some crypto venues group the fills of one taker order into one record, which is useful but changes what a line counts.
- The tape alone does not show cancellations: a bid that disappears without trading is visible only in the book.
- Speed makes lines unreadable; beyond a few updates per second the eye sees a scroll, not trades.
In Senzoukria
On a Rithmic connection, the Trading page places a trades tape next to the DOM ladder, with Time, Price and Size columns. Consecutive trades at the same price and side are merged when they arrive within 500 milliseconds, and a merged line displays how many trades it contains, so 400 contracts in one print and 400 in fifty orders do not look alike. A line is highlighted as large when its size reaches four times the median of the lines kept, once at least twelve lines are available. The tape keeps 400 lines, shows the latest 40 and refreshes four times a second; with no data it reads 'Waiting for trades' rather than claiming that nothing traded. Tape Speed and Big Trades carry the same information onto charts.
Related
In the same section
- Tick volume
- Take-profit
- Technical indicator
- t-statistic
- Testable hypothesis
- Systematic strategy
- Theta
- Survivorship bias
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Frequently asked questions
- Is tape reading still useful with footprint charts?
- A footprint is the tape sorted by price inside each bar, which makes the result of the flow easy to see but hides the order and pace of individual prints. Many traders use the footprint to locate where something happened and the tape, with the DOM, to watch it happen at a key level.
- What is the difference between tape reading and reading the DOM?
- The tape shows what has traded; the DOM shows what is waiting to trade. Reading them together answers the questions neither answers alone, such as whether a large displayed bid is being hit and holding, or disappearing without a single trade.