Replay speed and how it changes what you notice

Replay speed is the setting that decides how much market time passes in each second you watch. At 1 times speed, one second of market takes one second on screen. At 10 times speed, ten seconds of market pass in one second. This note takes one invented hour of ES, replays it in Liquivue at four speeds, and counts what each speed leaves on screen long enough to see. The note on replaying an imported recording in a browser platform covers the checks to run on the file first.

The recording in this example

All numbers below are invented. The file covers ES, the E-mini S&P 500 future, from 9:30 to 10:30 New York time. It holds three events.

1. A sweep at 9:31:12. Sell orders trade through six bid levels in 400 milliseconds. A sweep is a single burst of aggressive orders that trades through several price levels.
2. Absorption from 9:48:00 to 9:49:30. Sellers trade 640 contracts into one bid level that holds for 90 seconds.
3. A bid band at 5,060.00 that grows from 150 to 420 contracts over 20 minutes.

What each speed leaves on screen

A 60 Hz monitor draws a new frame about every 16.7 milliseconds. The table divides each event's market time by the replay speed, then counts frames.

At 10 times speed the sweep gets about two frames. The bands at six prices disappear between one frame and the next, and the trade bubbles appear on a diagonal at the same moment. You see that the levels went, but not the order they went in.

At half speed the same sweep takes 48 frames. That is enough to watch each band end in turn and count the bubbles at each price. The note on what a sweep looks like on a heatmap describes that picture at 1 times speed.

The band growth needs the opposite setting. At 1 times speed the change from 150 to 420 contracts takes 20 minutes, and the band brightens too slowly to see from one minute to the next. At 10 times speed it takes 2 minutes, and you can watch the colour change.

What changes inside each frame

Replay speed does not change the data. The same book updates and trades play in the same order. It changes how many of them land in each frame.

In this file the first minute after the open carries 4,000 messages a second. At 1 times speed that is about 67 messages per frame. At 10 times speed it is about 667. The platform applies every message to its book, then draws whatever state the book is in when the frame is due. Several short changes can start and finish between two frames, and those never appear on screen. A bid that flashes for 30 milliseconds at 1 times speed lasts 3 milliseconds at 10 times speed. It then has about a one in six chance of being in the book when the platform draws the next frame.

A two pass plan for the hour

Watching the full hour at 1 times speed takes 60 minutes. A two pass plan takes about 11.

1. Play the whole hour at 10 times speed, which takes 6 minutes. Write down the time of anything that looks like a sweep, absorption or a growing band.
2. Replay only the marked windows at a speed that suits each one. The minute around the sweep at half speed takes 2 minutes. The 150 seconds around the absorption at 1 times speed take 2.5 minutes.

The total is 10.5 minutes. Keep DOM order entry drills at 1 times speed. At 4 times speed you get a quarter of the market time to react, which does not match a live session.

Running the plan in Liquivue

Liquivue replays imported recordings in a desktop browser with WebGPU. During replay, the Liquivue heatmap layer draws resting size from the book updates, and trade bubbles print from the trade messages. The CVD panel steps down during the sweep and the absorption. Liquivue also lists absorption and sweep markers on its live heatmap. This site has not verified whether those markers run during replay, or which speeds the replay control offers. Check both during the 7-day trial before you plan a week of drills around them.

Liquivue costs €20 a month or €192 a year after the trial, and trade backfill covers 1 to 96 hours depending on the data provider.

Replay on other platforms

Bookmap lists recording and replay from its Digital+ tier on desktop. ATAS lists replay from its Plus plan, and its current connector notes exclude dxFeed instrument charts. Sierra Chart has synchronized intraday replay from historical chart data, with no historical market by order replay. Quantower replay takes tick, minute or day inputs. This site has not compared the speed controls on these platforms. The rankings page sets out replay coverage for each one.

A check you can run

Pick one sweep from a recording you trust. Replay it at 10 times, 4 times, 1 times and half speed. At each speed, write down how many price levels you saw the sweep take. Compare each count with the number of levels in the recording.