Hindsight Markets Beta

Day trading simulator · US equities · real market days

The whole market, replayed as it was.

From the scanners down to the order book. Pick a past day and the whole US market plays out live, pre-market to after-hours. Your scanners, news and filings run like they did that day, and fills come from the real order book, so you only get the shares that were actually there.

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Simulated trading. No real money. Not a broker, not advice.

The Scalper desk on 2026-09-16 at 11:16 ET: 1,000 MEDS held from 9.03 with a limit sell resting at 11.50, the scanner with MEDS near the top of the small-cap gainers up 506% on the day, time and sales, Level 2 by exchange, the order ticket and four charts of the run from 2 to 12, all on one clock.

How it works

  1. 1. Pick a day

    Choose a trading day and where to start it: the 4:00 pre-market open, the 9:30 bell, or any time you like. Each new trading day is added overnight.

  2. 2. Trade it as it happens

    The whole market runs from there. Find the mover on your scanner, pull it up, and trade it with your hotkeys or the order ticket. Pause, slow it to half speed, or run it up to ten times faster.

  3. 3. Review it

    Every trade is already in your journal, with its executions, its slippage and how far it went for you and against you. Open one and you are back at that moment, thirty seconds before you were in. Watch it with your fills drawn on the tape, or take it again.

Built for day traders and scalpers

The cockpit a DAS trader already knows, with a real market day behind it.

  • Hotkeys

    Buy, sell, cancel, cancel all, flatten, reverse. Every binding carries its own size, order type, price offset and route, with a confirm where you want one.

  • Every order type

    Market, limit, marketable limit, stop, stop-limit, trailing stop, bracket, range (OCO), MOO, LOO, MOC and LOC. Day, Day+ for extended hours, IOC and FOK, routed to the exchange you choose.

  • Level 2 and the tape

    The full order book, exchange by exchange, with your own orders marked at their price. SSR, borrow, halt and LULD tags in the header. Every print on time and sales, as it traded. See Level 2 and tape reading practice.

  • Charts

    Tick to monthly and any interval in between, a large library of indicators, a full set of drawing tools, and orders you can drag on the chart. Earnings, dividends, splits and filings are marked along the bottom as the clock reaches them.

  • News and fundamentals, point in time

    Headlines and SEC filings arrive at the moment they were published. Float, short interest, short volume and earnings are what was known by then.

  • Positions, orders and P&L

    Positions, working orders and every fill in their own windows. Flatten, reverse or close half from the row. Price alerts, and notes pinned to the moment you wrote them.

Time and sales, the open MEDS position with its resting exit, Level 2 exchange by exchange and the order ticket, at 11:16 ET on 2026-09-16.

Point-in-time scanners

Build a scan from gaps, relative volume at this time of day, float rotation, distance from VWAP, minutes since the high, minutes since news, short interest, short volume, days to cover, splits, earnings, sector and more. Rank the list and colour the columns the way you read them.

In a replay the scan reruns across the whole market every minute, and it only knows what the market knew at that moment. Click a row and that stock is on your chart, Level 2 and ticket. The usual scanners come ready: top gainers and losers, gappers, volume, relative volume, low-float small caps and after-hours gainers. More on the small-cap, low-float day trading simulator, and a morning it caught: why MEDS ran on 16 September 2026.

Check a scan before you trade it. The builder previews it against a past day at any time of day, pre-market included.

The scanner at 10:40 ET on 2026-09-16: the low-float gainers scan led by RETO up 409% and MEDS up 240%, with float and volume, under the MEDS chart and beside its Level 2 and time and sales.
The scan builder: market cap under 2B, float under 20M, change from close over 5%, with the preview of that scan at 10:40 ET on 2026-09-16 beside it.

SEC filings, as they came out

Every filing the SEC had accepted by that moment in the replay, in a reader built for traders. Offerings, ownership, insider trades, proxies, deals and delisting notices each have their own tab, and a filing that lands while you watch is marked new. One from later in the day will not open.

A filing opens on its own page, the way the company filed it, with its exhibits one click away, an outline to jump through and a search box. On the chart, the filings that move a stock, like 8-Ks, offerings and late-filing notices, sit on the day they came out: hover one to read it, click it to open it.

The Filings window beside the MEDS one-minute chart at 11:00 ET on 2026-09-16: the list of MEDS filings up to that moment (the proxy statement, 8-Ks, the 10-Q, the late-filing notice, the S-1 and insider forms), and the 10-Q open on its own page with its exhibits and its outline.

One day, the whole market

A replay is a day, not a symbol. Pull a name in from a scanner row, a watchlist or the search box and the chart, book, tape and ticket follow it. One account and one P&L across everything you touch.

You run the clock. Start at 4:00, at the bell or at any time. Pause, step a bar at a time, run from half speed to ten times, or jump straight to a time. Go back and the market rewinds with you, so you can take the same trade again. How a stock market replay works, step by step.

The command palette with QC typed, listing the tickers that match, each one a keystroke from being added to the running replay.

The real order book, and the real rules

Your orders meet the book that was there that day, under the rules that applied that day. Each rule is explained in the day trading glossary, and the free trader tools work it out for any date.

MEDS at 10:48 ET on 2026-09-16, halted on a LULD pause: time and sales shows no prints, Level 2 shows the resting depth still streaming, beside the one-minute chart.

What is not modeled: hidden liquidity never fills you, and your own order does not move the market after it fills. Off-exchange trades fill a resting limit only during regular hours, and only when they print through its price, not at it. The full list is on the disclaimer page.

The journal writes itself

Every trade is recorded with its executions, its slippage against the book, and how far it went for you and against you. Open one to see it on the chart with VWAP, the 9 EMA, SPY and the tape at each fill, and what it would have made if you had held on or sold at the best price. From there you are back at that moment, thirty seconds before you were in. Watch it with your fills drawn on the tape, or take it again. The first attempt is the one that counts; every attempt after it is practice, shown beside it and never counted.

Set a stop and every result reads in R. Write your playbooks and their rules, tag your mistakes, grade the trade, and see which setups pay by playbook, time of day or hold time, one month against another. The calendar shows every day at a glance, and each day and week has its own notes. It also flags the revenge trade, the overtrading and the loser you held.

Bring in your real trades from your broker's own export, from DAS Trader, TradeZero, Lightspeed, Interactive Brokers, thinkorswim or Webull, or any file of fills with times. They sit beside your replay trades without mixing into them. Open one and you are back at that moment on any day since August 2026, to watch it or take it again. Export everything.

The trades table: four round trips on 2026-09-16 across MEDS and RETO, two winners and two losers, each with its path, entry, exit, hold time, fees, excursion, efficiency, slippage and P&L.
One RETO trade opened: the chart with entry, exit, stop and the best and worst points marked, the trade's numbers and auto note, and the trader's own read (stop, target, playbook and grade).

Laid out like your desk

Dock, tab and resize every window. Start from a built-in layout (Scalper, Scanner day, Research or Classic) or save your own. Keep several screens under one clock and one account, and pull any of them onto another monitor. Link windows by colour so they follow the same symbol. Pick how tight the windows are, Comfortable, Compact or Dense, for the whole desk or one window, and hide any bar you do not use. Light or dark.

The layout menu open over the workspace: the built-in layouts Scalper, Scanner day, Research and Classic, a saved layout called Momentum, and the controls to save your own.

Questions

Is this real money?
No. Every order is simulated against historical market data. No order reaches an exchange or a broker, and nothing here is financial advice.
Which days can I trade?
Every trading day from August 2026 forward. Each new trading day is added overnight.
Can I use it at night or on weekends?
Yes. The days are recorded, so the market is open whenever you are.
Can I trade pre-market and after-hours?
Yes. A replay covers pre-market, regular hours and after-hours, and the book, tape and scanners run through all of it.
Do I pick one stock per replay?
No. A replay is the whole market on one day. Switch symbols from a scanner, a watchlist or the search box as often as you like; your account and P&L follow you.
Which stocks are covered?
Every stock, ETF and warrant listed on a US exchange. OTC stocks are not included.
Can I short?
Yes. The Level 2 shows SSR and borrow status, a hard-to-borrow stock needs a locate first, and shorting a stock under five dollars takes cash instead of leverage.
Is it a backtester?
No. You trade by hand, at market speed or faster, the way you would on a live day. Nothing here runs a strategy for you.
Do I need a broker account or a market data plan?
No. There is nothing to connect. Everything you see is included.
Can I bring in my real trades?
Yes. Import your broker's export and your trades land in the journal, kept apart from your practice. For any day from August 2026 on, you can open the market that day and go back to the moment you were in.

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