How to Read Time and Sales: Prints, Size and Conditions

Time and sales is the record of trades that have already happened. Each line is one execution: the time it was reported, the price, the number of shares, and on most screens the venue that reported it plus a condition code if the trade was out of the ordinary. New prints arrive at the top. On a busy stock the list scrolls faster than anyone can read it.

Most platforms also color each print. A trade at or near the ask gets one color, a trade at or near the bid gets another, and anything in between gets a third. That coloring is handy. It’s also the platform’s guess, which matters more than it looks.

Trades on one screen, orders on the other

Level 2 quotes show orders waiting to trade. Time and sales shows orders that did trade. They answer different questions. Traders who watch one usually keep the other open beside it.

A bid for 2,000 shares on the book is an intention. It can be canceled before anyone touches it. A print of 2,000 shares is finished business, since someone bought, someone sold, and the price is fixed, which makes a print firmer evidence than a displayed order even though it gives you no name, no motive and no hint of whether the buyer has more shares left to buy.

What each column tells you

Time is when the trade was reported. That’s usually close to when it happened. Price and size are what everyone watches. The venue column names the exchange, or carries a code for a trade reported from off exchange.

Then there’s the condition column. People skip it. Skipping it is behind most of the confusion about strange prints, because the condition is where the tape tells you a trade was reported late, priced by some method other than the live market, or done outside regular hours.

Reading the tape against the quote

Start with where the trades land. Say the quote is 25.10 bid and 25.12 offered. If prints keep coming at 25.12, buyers are paying the offer to get filled, which traders call lifting the offer. Prints at 25.10 mean sellers are hitting the bid. Prints between the two often come from off-exchange fills or hidden orders inside the spread.

Next, see whether the pattern holds. One print at the ask means little. A string of them, with the offer stepping up a cent and the prints following it up, says that buyers have kept paying up for that stretch of trades.

Watch the speed. A tape that prints every few seconds and then suddenly prints many times a second is telling you activity picked up, which can come with news, with a price level a lot of traders are watching, or with a large order being worked in pieces.

Large prints draw the eye. A single trade far bigger than the sizes around it may be a block done in one go, or one slice of something larger that is still being worked. Check its condition before you read anything into it, because some of the biggest prints on any tape were reported late or priced by agreement away from the quote.

None of this predicts the next trade. The tape describes the last few seconds or minutes in detail, and a run of buying at the ask can be followed by a stall or a reversal with nothing on the screen to warn you which.

A hypothetical sequence of prints

Here’s a made-up stretch of tape for a stock quoted at 25.10 by 25.12. Every number is hypothetical.

Time	Price	Size	Quote at the time	Side shown
10:31:02	25.12	200	25.10 x 25.12	Ask
10:31:02	25.12	100	25.10 x 25.12	Ask
10:31:03	25.12	500	25.10 x 25.12	Ask
10:31:03	25.13	300	25.11 x 25.13	Ask
10:31:04	25.11	100	25.11 x 25.13	Bid
10:31:05	25.13	1,000	25.11 x 25.13	Ask
10:31:05	25.12	37	25.11 x 25.13	Between
10:31:06	25.05	5,000	25.11 x 25.13	Flagged: average price
10:31:06	25.13	400	25.11 x 25.13	Ask

Read it from the top. The first three prints take the offer at 25.12 for 800 shares between them. Then the quote moves up a cent on both sides. After that, nearly everything prints at the new ask of 25.13, the 1,000-share trade included. One 100-share print hits the bid. The 37-share trade is an odd lot printed between the bid and the ask, the kind of fill that often comes from an off-exchange venue.

The 5,000-share print at 25.05 carries an average-price condition. A trade like that is priced from a set of earlier executions and reported as one line, so its price says little about where the stock stood at that second. Leave it out.

So what does the sequence suggest? For those few seconds, buyers were the side willing to cross the spread, and they kept doing it after the quote moved up. That’s a description. It might be one buyer working a bigger order. It might be a burst of small market orders from many accounts, and it might reverse a minute later.

Adding up volume by side beats squinting at colors. Run the same price-times-size arithmetic over every regular print in the session and you have VWAP, which is why the two are often read together.

Why the colors are a guess

A trade report carries price, size and time. It doesn’t say whether the buyer or the seller started the trade, so the platform compares each print with the quote it had at that moment and labels it from there.

Two problems follow. Quotes and trades travel on separate data, so on a fast stock the quote the platform compares against may already be out of date by the time the print arrives. And a print inside the spread has no clear side, so it gets a neutral color or a best guess. The colors hold up better on a slow stock than on a fast one, where the quote can change several times between trades. Treat them as a rough sort.

Prints that look odd for a reason

Trades executed away from the exchanges are reported to the tape too, usually with a venue code for the facility that took the report. They’re real trades. They just never sat on the public book, so you won’t have seen the order behind them on Level 2.

Odd lots, trades under 100 shares, appear as well. Tiny prints can make a stock look busy. Very little size may be changing hands.

Some trades are reported late or out of sequence. They carry a flag and can show a price from earlier in the session. Average-price trades, like the one in the table, take their price from a group of earlier fills. Prints from before the open and after the close carry their own extended-hours condition, the one often called form T.

Those conditions reach the chart. Prints with certain flags are excluded from the last sale and from a bar’s open, high, low and close, so a tape can show a trade at a price the chart never reached.

Your price printed and your order sat there

Go back to the table. At 10:31:04, 100 shares printed at 25.11. If you had a buy limit resting at 25.11, you’d see a trade at your price and your order still open.

Orders at the same price generally fill in the order they arrived, so that 100-share print may simply have filled someone who joined the bid before you did. An off-exchange trade at your price can print without coming near your order, because it happened at a venue where your order wasn’t resting. The other common causes, from time in force to session settings, are covered in why a limit order doesn’t fill when the price touches it.

What the tape can tell you is how much volume traded at your level. If heavy volume prints at your limit and the order stays open, check its status and time in force first.

Checking it on your own screen

Open time and sales on a stock you trade. Look at the column settings. See whether the screen shows venue and condition, and whether it filters any conditions out by default, since some screens hide odd lots or extended-hours prints until you switch them on.

Then find the help page that explains the colors. You want to know which quote it compares each print against and how it labels a trade inside the spread. After that, the colors are one more column to weigh.