Guide 3.3
Beginner, 5 min read. Checked with Scalpel 1.12.8 on .
In short
The time and sales tape is the narrow column on the right of Scalpel's Level 2 panel: every trade in the stock, newest on top, with its price and size. Green bars are buyers taking the ask, red bars are sellers hitting the bid, grey rows traded in between, and each bar's length is the trade's size against the biggest one around it, so block trades stand out. The book shows what people are willing to do; the tape shows what they actually did.
Level 2 can be faked: orders are placed and pulled all day. Trades cannot. Reading the tape (also called time and sales, or prints) tells you whether buyers are actually paying up, how big they are, and how fast it is happening. On a momentum stock that is often the earliest sign a move is starting or running out.
Before you start
Each row is one trade (a print):
The side a trade is counted on is its aggressor, the one who crossed the spread. Buyers lifting the offer is the side that pushes price up.
Read the tape against the book. The ask says there are 245 shares at 5.71; if 2,900 shares trade there and 5.71 is still offered, there was far more than the book showed.
The tape's options are in the LEVEL 2 cog, under Time and sales (guide 2.3). They apply to every desk.
| Option | Default | Use it when |
|---|---|---|
| Display min size | 0 | A busy stock prints hundreds of odd lots a second. Set 100 to hide anything under 100 shares, or 500 to see only the bigger players. The delta, read line and tape sound still count every print. |
| Color by aggressor | On | Leave on. Off draws every print grey. |
| Size bars | On | Off paints whole rows in green or red instead of bars: easier to read the colour at a glance, harder to spot the big prints. |
| Dollar value instead of size | Off | Shows price x size in whole thousands: the 2,500 shares at 5.71 read $14K, and anything under $500 reads $0K. The header changes to VALUE. Handy when you trade both $2 and $20 stocks, since 1,000 shares means very different money on each. |
Show tape column in the Level 2 section of the same cog hides the tape completely, giving the book its full width. Tape sound keeps playing (guide 3.4).