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das/replay
Beta
A market replay trading desk

The day, replayed.
The desk, professional-grade.

An advanced market replay trading desk that emulates Lightspeed, DAS Trader, and Sterling — driven by real historical tape, real NBBO, and real scanner alerts firing at the exact times they fired in the live market. With a real fill engine on top.

$ join the beta How the replay works

Early access Private beta — seats open in waves. Request one and we'll wire up your desk.

Tick-level NBBO Real scanner alerts Deterministic under seed
The workspace

Lay out the desk the way you trade.
Then span it across monitors.

Every panel is a window. Drag, dock, split, and tab them into the layout you actually run — four charts at different timeframes, the Level 2 montage, the order ticket, scanners — then save it, name it, and load it next session.

Pop any window out as a real OS window and slide it to a second monitor. The pop-out runs on the same session and the same socket — not a second connection — so a detached chart ticks in lockstep with the docked one.

Up to 6
panes per pop-out
Real OS
windows, any monitor
Saved
named layouts
  • Chart
  • Level 2
  • Order Entry
  • Time & Sales
  • Orders
  • Positions
  • Stock Quote
  • Alerts
Why this exists

Chart-replay tools paint candles. Paper accounts fill you on the mid. Neither shows you what the day looked like through a working trader's screen.

The desk plays back the real tape — every NBBO update, every print, every condition code — for the names that actually moved that day, surfaced by the scanners you'd have been watching.

Real tape. Real fills. Real diagnostics.

Four claims that separate this desk from every chart-replay tool, paper broker, and synthetic simulator on the market. Each one is the literal thing the engine does — not a metaphor for it.

Real historical NBBO

Every quote, every print — sourced from the actual tape.

The Level 2 ladder, the time-and-sales strip, the chart — all driven by tick-level historical data: NBBO with bid/ask sizes and exchange routing, trade prints with full condition codes (A, B, H, O, W, C, L, 4, 5, 6, 7, 9), 04:00–20:00 ET extended hours. A quote-eligibility filter drops manual, stale, crossed, and condition-flagged quotes so fills never evaluate against bad NBBO. Nothing is painted; nothing is synthesized.

Tick-level · NBBO · NSDQ · ARCA · BATS · EDGX · NYSE · AMEX

▲ PLSM
13.61
TierN1
Close3.41
Last13.61
Hi13.82
Open3.86
Vol5.15M
Lo3.80
Chg+10.20
Chg %+299.12%
MktBid
EDGX 13.57 1
PHLX 13.56 2
ARCA 13.53 2
IEXG 13.52 1
BATS 13.51 1
AMEX 13.50 1
EDGX 13.49 1
EDGA 13.48 1
PriceMkt
13.61 5 ARCA
13.62 3 NSDQ
13.63 3 NYSE
13.64 1 PHLX
13.65 1 IEXG
13.67 2 NSDQ
13.68 1 ARCA
13.69 1 ARCA
Real scanner alerts

Two scanners. Real triggers. Revealed in order.

Top Leading Gainers and High-of-Day Momentum run against the real tape of the day you picked. Hits fire at their exact historical timestamps — the same trigger logic, the same metadata (pump %, prior HOD, breakout volume), the same order. Click any alert to jump the desk to that ticker at trigger time minus ten seconds, so you see the print that triggered the scanner, not just the print.

Top leading gainers · High-of-day momentum · Premarket + regular + post

Alerts +8
8/66 (live)
TimeTickerPriceVolFloatRVOLType
  • 07:30:48 TLSA $1.86 71K — — Up 10% in 10min
  • 07:27:56 GNTA $1.85 6.3K — — Up 10% in 10min
  • 07:23:07 MIST $3.52 3.2M — — 52wk Breakout
  • 07:15:55 XCUR $6.43 6.0K — — Up 10% in 10min
  • 07:05:52 EZGO $2.54 2.0K — — 52wk Breakout
  • 07:02:34 NCEL $3.47 230 — — Up 10% in 10min
  • 07:01:38 ARBB $8.94 116K — — Up 10% in 10min
  • 07:00:27 IMNM $22.30 52K — — 52wk Breakout
Real fill engine

A matching engine, not a chart marker.

Orders submit through a latency profile (retail 180ms ±40, direct-access 120ms ±25, colo-pro 30ms ±10, or custom), evaluate against the real NBBO at submit time, and fill against it at the latency-adjusted clock. Marketable orders walk the book with penny-floor slippage attribution. Resting limits sit behind a synthetic queue with time-decay stale-skip. Cancel races resolve in tick order.

Latency-profiled · Queue-aware · Walk-the-book · Cancel races

Orders
StatusSymbolSide QtyLimitFillTime
FILLED PLSM B 100 / 100 11.42 11.2556 07:19:50
Positions
SymbolCost basisQtyUnrealized P&LRealized P&L
PLSM $11.2556 100 +$233.44 $0.00
Slippage diagnostics, per fill

Three NBBO snapshots and a breakdown on every order.

Every fill carries the NBBO at submit, the NBBO at evaluation, and the NBBO at fill — so you can read exactly what happened on the order. Slippage is decomposed into chasing bps (penalty when the tape moved 20+ bps in the 2s before fill), late-entry bps (time-decay on resting orders), and spillover bps (the cost of walking the synthetic book). Sub-penny precision throughout.

Chasing · Late-entry · Spillover · Sub-penny attribution

The session loop.

The desk runs a session the way a trading day runs: pick the date, pick the scanner, take the trades, read the fill log. No green arrows. No "are you sure?" No coaching mid-session.

  1. 01 Stage

    Pick a day. Pick a scanner.

    Choose any historical trading date and one of two scanners — Top Leading Gainers or High-of-Day Momentum. The desk loads the real tape, the real NBBO, and the same scanner triggers that fired live on that day. Start the session at any minute between 04:00 and 20:00 ET.

  2. 02 Stage

    Trade as the day plays out.

    Alerts arrive when they arrived, in the exact order they arrived. Chase a name, jump back ten seconds to see the print that triggered the alert, work the L2 ladder, send orders through a real fill engine with seeded latency and walk-the-book mechanics. Hotkeys, pop-out windows, multi-monitor — the cockpit you would have been using.

  3. 03 Stage

    Read what actually happened.

    Every fill carries three NBBO snapshots — submit, evaluation, fill — plus the latency draw and a slippage breakdown by source (chasing, spillover, late-entry). The session lands in the journal; the career view aggregates. No coaching, no nudges. The fill log is the debrief.

The desk

Eleven panel types. Real OS pop-outs. Saved layouts.

A Dockview-based workspace built the way a working trader builds one: drag, dock, split, tab, resize, save, restore. Pop panels out as real OS windows — same WebSocket, same context — and drag them to a second monitor.

  • Session header ticker · last · bid/ask · spread · % change · RVOL · float
  • 10s chart 8 indicators · 5 drawings · execution markers
  • Level 2 montage green/red ladder · MMID · LULD flag · inside row
  • Time & Sales tape aggregated prints · uptick/downtick · large-print flag
  • Order entry ticket Lightspeed-style · tick-aware to $0.0001 · Inside Bid/Ask
  • Orders table pending · working · partial · filled · cancelled · rejected
  • Positions table open · pending-sell · realized + unrealized P&L · NBBO mark
  • Quick-actions panel mirrors the hotkey bindings · trackpad-equal
  • Replay controls 0.1× – 10× scrub · pause · candle-index · seek
  • Alert feed rail scanner-day clock · reveal-on-trigger · click to jump
  • Session metrics P&L · drawdown · trade count · win rate · duration
  • Custom pop-outs Build any combination · 1 or 2 columns · up to 2×3 grid · real OS windows · drag to a second monitor
8 INDICATORS
5 DRAWING TOOLS
5 TIMEFRAMES
4 LATENCY PROFILES
The journal

Every session lands in the journal.

Close a session and it posts to the calendar — a month heatmap where the color is your realized P&L, not a streak badge. Click a day and the debrief opens: every session, every execution on the chart, and the per-trade stats that say what actually happened. No coaching. The fill log is the lesson.

June 2026
Month P&L+3110.00
Traded days20
Sessions35
Win days13 / 7
Best+1840.00 · Jun 24
Worst-420.00 · Jun 19
Sun
Mon
Tue
Wed
Thu
Fri
Sat
1 -120 2t
2 +85 1t
3 +240 3t
4 -310 2t
5 +60 1t
6
7
8 +420 2t
9 -90 1t
10 +180 2t
11 +95 1t
12 -240 2t
13
14
15 +610 3t
16 -150 1t
17 +330 2t
18 +70 1t
19 -420 2t
20
21
22 +260 2t
23 +140 1t
24 +1840 3t
25 -180 1t
26 +290 2t
27
28
29
30
2026-06-24
Day P&L+1840.00
Sessions3
Tickers3
Trades16 · 56%
Sessions 3
PLSM 7:11a +1624.00
9 trades · 67%
AABB 9:42a +290.00
4 trades · 50%
XTIA 10:15a -74.00
3 trades · 33%
PLSM 2026-06-24 · 07:11 ET
Buy Sell
BUY 07:11:30 400 @ 4.62
BUY 07:14:05 300 @ 5.31
SELL 07:16:12 400 @ 7.94
BUY 07:16:48 200 @ 8.70
SELL 07:18:20 300 @ 9.58
Stats PLSM
Net P&L 18m 20s
+1624.00
Gross +1689.40 · slippage -65.40

Win rate

6 / 3 67%

Trade economics

Trades9
Avg win+412.30
Avg loss-198.50
R-multiple2.08R
Max drawdown-340.00

Excursion (MFE / MAE)

MFE+2100.00
MAE-260.00

Captured 77% of the favorable swing.

Cash

Starting$25,000.00
Ending$26,624.00

The day, replayed.
The desk, professional-grade.

$ join the beta Or read the methodology first

Early access Private beta. Real tape, real fills — request a seat.