# Single Prints A Volume & Order Flow concept (Market profile / auction theory) in the LuxAlgo Library, with 1 indicator implementation. ## What are Single Prints? Single prints are price levels in a [TPO profile](https://www.luxalgo.com/library/concept/tpo-profile/) that traded during only one time bracket, leaving the profile exactly one letter wide there. When they sit inside the body of the profile rather than at its extremes, they record a fast, one-directional move: price transited those levels so quickly that no later period returned to trade them. Auction theory reads that thinness as initiative activity that left an unfinished, one-sided auction behind. Convention matters here: single prints at the very ends of a session's profile are called buying or selling tails and signal rejection, so the term usually refers to the mid-profile kind. Traders treat them like other thin structures, close cousins of [low-volume nodes](https://www.luxalgo.com/library/concept/high-low-volume-nodes/) and the price-action [fair value gap](https://www.luxalgo.com/library/concept/fair-value-gap/): potential support or resistance while intact, and a candidate for repair when price returns to auction the area properly. Neither the hold nor the fill is guaranteed. The mechanics come from how TPO charts are built. Each half-hour bracket of the session gets a letter, and every price the market touches during that bracket collects that letter; a row with exactly one letter is a price the market visited during exactly one half hour of the day. Mid-session, that status is provisional, since any later bracket can rotate back and thicken the row; only the closing bell freezes the day's singles. The vocabulary belongs to the Market Profile tradition of Steidlmayer and Dalton, where singles sit alongside related unfinished structures: poor highs and lows, extremes that end flat and untapered, carry a similar incomplete-auction message from a different shape. Practical treatment is bookkeeping plus patience. The single-print range is marked by its edges, because a return to the zone tends to be judged there first, and it stays on the map until repaired, meaning a later session rotates through and auctions the area properly, at which point the level retires. Trackers like benb1122's TPO Levels study automate the ledger, carrying singles forward beside value areas, poor extremes and naked POCs. The honest framing matches the rest of the profile toolkit: these are well-defined reference zones with auction logic behind them, not statistical guarantees, and recent singles from the current volatility regime deserve more attention than relics. ## How to identify single prints The definition is mechanical, so identification is mostly about location and timing. 1. Build the session's TPO profile with standard half-hour brackets, each contributing its letter to every price it touched. 2. Find rows exactly one TPO wide: prices the market visited during only a single bracket of the session. 3. Classify by location: singles at the profile's extreme top or bottom are tails, rejection structures; singles inside the body are the fast-transit kind the term usually means. 4. Wait for the close before trusting the label, since any later bracket can rotate back and thicken a provisional single into ordinary structure. 5. Mark the single-print range by its edges and carry it forward; the first return to those edges is where the repair-or-reject question gets answered. ## How traders use it - As reference levels: the edges of a single-print range are common spots to watch for a reaction on first retest, on the logic that a move fast enough to leave singles may be defended where it started. - As unfinished business: when price rotates back, traders watch whether the thin zone fills in period by period (repair, which retires the level) or gets rejected quickly (the original imbalance is still being defended). - As a day-type tell: fresh single prints appearing mid-session mark initiative range extension and argue against fading the move, while their absence keeps the day in balanced, rotational territory. - In value-map context: singles connecting two balance areas act as thin corridors, so acceptance back into the zone often travels quickly across it toward the far [value area](https://www.luxalgo.com/library/concept/value-area/) and its [point of control](https://www.luxalgo.com/library/concept/point-of-control/). - As part of an unfinished-business ledger: singles, poor highs and lows, and naked POCs tracked together give swing traders a running list of prices the auction still owes attention, with each item retired as the market repairs it. ## Single prints vs related thin structures - **TPO Profile** (https://www.luxalgo.com/library/concept/tpo-profile/): The profile is the lens, singles are one artifact seen through it: rows exactly one bracket wide. Without the TPO construction the concept does not exist, which is why volume-based charts need analogous but distinct vocabulary for their thin zones. - **High/Low-volume Nodes** (https://www.luxalgo.com/library/concept/high-low-volume-nodes/): A low-volume node is thinness measured in contracts traded; a single print is thinness measured in time spent. The two usually coincide across a fast move but need not, and each catches cases the other misses: a brief but heavy stop-run prints singles without a volume hole. - **Fair Value Gap** (https://www.luxalgo.com/library/concept/fair-value-gap/): The FVG is candle arithmetic, a three-bar imbalance visible on any chart; singles are session-profile structures confirmed only at the close. Both mark one-sided delivery expected to be revisited, so they frequently nominate the same zones from different clocks. ## FAQ ### What is the difference between single prints and tails? Both are one TPO wide, but location changes the meaning. Single prints at the extreme top or bottom of the profile are tails: responsive traders rejected those prices quickly. Single prints inside the body mark a fast initiative move that never received a second auction. Tails signal rejection; mid-profile singles mark thin, unfinished trade that often gets revisited. ### Do single prints always get filled in? No. Many are repaired when price rotates back and auctions through them, but some hold as support or resistance for days or weeks, and some are never revisited at all. Treat a fill as a scenario with a reference level attached, not a certainty, and note that once repaired the zone loses most of its significance. ### What bracket length do TPO charts use for singles? Thirty minutes is the classical convention, inherited from the pit-session structure the methodology grew up in. The choice matters: shorter brackets multiply letters and make singles rarer and finer-grained, longer brackets do the reverse, so a level that is a single print under one bracket length may not be under another. Whatever bracket you analyze with, keep it constant so your ledger of singles stays comparable. ### How do single prints differ from poor highs and lows? Both are unfinished-auction structures, distinguished by shape and location. A poor high or low is an extreme that ends flat, two or more TPOs wide at the very top or bottom, lacking the taper of genuine rejection; the auction ran out of time rather than out of buyers or sellers. Singles inside the body are speed scars from initiative moves. Poor extremes suggest revisiting the extreme; singles suggest repairing the corridor. ### Is there a volume-profile equivalent of single prints? The closest analog is a pronounced low-volume zone in a [volume profile](https://www.luxalgo.com/library/concept/volume-profile/): both mark prices the market did not genuinely accept. They measure different things, time brackets versus contracts traded, and diverge in instructive cases, like a brief, violent stop-run that concentrates heavy volume into a single bracket. Profile traders often track both, treating agreement between them as stronger evidence of a thin zone. ### When do old single prints stop mattering? Formally, when repaired: once a later session rotates through and auctions the zone properly, the structure is retired. Informally, relevance decays with age and regime change, since a corridor left by a news spike three months ago in a different volatility regime says little about today's participants. The working practice mirrors other profile references: recent, nearby, unrepaired singles get weight, and the archive gets respect only at first touch. ## Implementations in the Library - Single Prints (LuxAlgo): https://www.luxalgo.com/library/indicator/single-prints/ ## Related concepts - Initial Balance: https://www.luxalgo.com/library/concept/initial-balance/ - TPO Profile: https://www.luxalgo.com/library/concept/tpo-profile/ - Unfinished Auction: https://www.luxalgo.com/library/concept/unfinished-auction/ - Excess: https://www.luxalgo.com/library/concept/excess/ - Balance vs Imbalance: https://www.luxalgo.com/library/concept/balance-vs-imbalance/ - Rotation Factor: https://www.luxalgo.com/library/concept/rotation-factor/ - One-timeframing: https://www.luxalgo.com/library/concept/one-timeframing/ - Day-type Taxonomy: https://www.luxalgo.com/library/concept/day-type-taxonomy/ - Value Migration: https://www.luxalgo.com/library/concept/value-migration/ - 80% Rule: https://www.luxalgo.com/library/concept/80-percent-rule/ --- Source: https://www.luxalgo.com/library/concept/single-prints/ (LuxAlgo Library, the encyclopedia of trading & technical analysis). Free to use with attribution: https://www.luxalgo.com/library/license/