Sierra Chart Replay Not Working: The Documented Causes

Sierra Chart's own documentation names six separate things that look like a broken replay: no new bars appear, the replay pauses and waits, the control panel never opens, the data cannot be replayed at all, a second window falls out of step, or the interface freezes. Each has its own documented cause, and the fixes point in different directions, so the first job is to name which one you have.

Sierra Chart tells you to raise the speed to prove the replay is running, drop it to 1 to get past a quiet market, and keep it at 50 or less to stop the interface freezing. All three instructions are theirs, and each belongs to a different symptom.

Why is my Sierra Chart replay not working?

No new bars appear

The usual cause is a low speed against coarse underlying data: "You are running a replay at too slow of a speed, Speed = 1.0 (equivalent to real-time), and the underlying data in the data file has a high timeframe per record such as 1 Minute. Therefore, you would only see a new bar appear every minute." Infrequent trading at the time you are replaying does the same thing.

Sierra Chart's first instruction is to raise the speed: "Try increasing the Speed to 120. If that speed does not cause new chart bars to appear, increase the Speed to 1440 for the purpose of confirming the replay functionality is working."

A third cause sits below the chart, in how the data was stored. An Intraday Data Storage Time Unit of 1 Minute at speed 1 gives you no update "more often than in 1 minute intervals", and changing the setting means re-downloading the symbol, because the change "will not affect the existing data in the file."

Damaged data is the last one. Where the chart holds missing or out of order data, Sierra Chart tells you to re-download all of it with Edit >> Delete All Data and Download.

The replay pauses and waits

This one is working as designed: "when periods of no trading are encountered in the Intraday chart, that the replay will pause until the replay time, which is affected by the replay speed, catches up to new data." Skip Empty Periods jumps any gap of "65 seconds or more" instantly.

The instruction here runs the opposite way from the one above: "it is recommended reduce the Replay Speed to 1 and enable Skip Empty Periods." A higher speed makes a quiet patch more likely to stall the replay, "because the amount of time to wait will be less than 65 seconds because of the acceleration."

The replay window never appears

Reset its position. If the Replay Control Panel does not appear when you select Chart >> Replay Chart >> Replay Chart, Sierra Chart's fix is Chart >> Replay Chart >> Reset Replay Control Panel Window.

If the keyboard shortcut is what does nothing, they say to check whether the key is assigned elsewhere, and note that the operating system may be capturing it before the application sees it.

Nothing can be replayed at all

Check the file format first: "Only Intraday data in the Sierra Chart scid (Sierra Chart Intraday data) file format can be replayed." Intraday data held in a text format has to be imported before it will replay.

Daily and higher timeframes are the other reason. Historical Daily, Weekly, Monthly and Yearly charts opened through Open Historical Chart cannot be replayed, with a documented workaround covered below.

A second chart or a Trade DOM falls out of step

Several settings have to line up, and there are several ways to get it wrong. Every other chart's Days to Load for Intraday Chart Data Type must be "set to the same or greater value than the chart you are controlling the replay from", and "By default Trade DOMs only load 1 day." Session Times "should be identical for all the charts or they should be set to 00:00:00 to 23:59:59."

For a Trade DOM, two settings are called out as essential: a Days to Load value that covers the period you are replaying, and the time zone, where "The Time Zone setting must match the Time Zone setting in the chart the replay will be started from." If the controlling chart has Continuous Futures Contract switched on and uses an identical symbol, the DOM's Continuous Contract setting has to match it too. Sierra Chart's advice is to drive the whole thing from one window: "It is most reliable to start the replay from a standard chart and control the Trade DOM replay from there", then select Charts to Replay >> All Charts in Chartbook.

There is a conflict buried in that group. Skip Empty Periods is the setting that cures a replay stuck on a quiet patch, and it is also the setting you have to switch off to keep two windows together: "it is necessary to disable Skip Empty Periods on the Replay Control Panel window to prevent any loss of synchronization between the charts and Trading DOMs as the replay progresses through." The replacement is manual: "increase the Replay Speed to a significantly higher setting or Jump Forward."

The interface freezes

The freeze warning is scoped to one mode. In Accurate Trading System Back Test Mode, Sierra Chart says "momentary freezing of the Sierra Chart user interface is not unusual", because the mode does a large amount of processing before yielding back to the interface.

Their fixes are Safe Mode when custom studies are using heavy CPU, "Set the Replay Mode to Standard", "Use a lower Replay Speed like 50 or less", and an Intraday Data Storage Time Unit of "1 Second or higher".

Can you start a Sierra Chart replay at a specific date and time?

There is one setting for it, Use Start Date-Time, and Sierra Chart's documentation tells you never to use it. The replay page carries both the instruction and the prohibition, so a trader following it in good faith can end up on either side.

The prohibition, in its own section: "It is strongly recommended to keep Use Start Date-Time, disabled and never use it. It is the source of so many replay problems." It goes further: "Sierra Chart support will provide no technical support at all when using this option. We will insist that you disable it and never use it. Once again do not use this setting! Do not use it!"

Step 3 of the basic instructions carries the exception and the refusal in one breath: "Important: On the Chart Replay window be sure to uncheck Use Start Date-Time unless you want to specify the starting Date and Time directly on the Chart Replay control panel. WARNING: Do not use this setting!"

The section headed Replaying Chart from Specific Date-Time then instructs the opposite: "On the Replay control panel, enable the Use Start Date-Time option", with the date as YYYY/MM/DD and the time as hh:mm:ss. The next section opens by assuming you did: "These instructions assume that you are using the Replaying Chart from Specific Date-Time." On the backtesting page the manual route says it the other way again: "Make sure the Use Start Date-Time option is disabled."

The reason behind the warning is a real failure mode. Set a date-time earlier than the first one loaded in the chart and "then you will not be replaying data from that date-time and there will be limited amount of data in the chart at the start of the replay." The supported alternative is to scroll back by hand, or press Home.

One more cause of a replay that seems to begin in the wrong place has nothing to do with that setting: the replay clock runs while the chart loads. Sierra Chart's example uses a speed of 60 and a ten second load, and concludes that "although the chart will actually indeed start at the specified Date-Time, you will notice that it seems to start at a time which is 10 minutes later."

How do you start a Sierra Chart replay, step by step?

Their Basic Chart Replay Instructions, condensed:

1. Open or go to a standard chart. "A replay can only be started from a standard chart. A replay cannot be started from a Trading DOM window which has no scrollbar, and no visible bars loaded."
2. Select Chart >> Replay Chart >> Replay Chart (Control Panel), or press the Rpl button on the Control Bar. On a detached chart, use that chart's own menu so the replay window opens with the detached chart as its owner.
3. Leave Use Start Date-Time unchecked.
4. "Scroll the chart back to where you want to begin the replay." Home goes to the beginning. If you cannot scroll back far enough, raise Days to Load for Intraday Chart Data Type in Chart >> Chart Settings >> Data Limiting.
5. Set the Speed. For a first run they suggest "about 30 or 60 times in order for it to be more obvious a replay is occurring."
6. Set Charts to Replay. "If you are just getting started with chart replay, we recommend using just Single Chart."
7. Press Play, then answer the Clear Trade Data prompt.

A trader practising a setup usually wants the other route, one bar at a time. Set the Jump Method to To Next Bar and press Jump Forward: "Each time the Jump Forward button is pressed, the chart will advance by one bar and the next bar displayed will be complete." On that route, "The Speed setting does not matter and can be anything."

Which Sierra Chart replay mode do you want?

Standard Replay, if you are a person taking trades rather than testing a program. Their own instruction: "Use Standard Replay when not performing back testing of an automated trading system and only performing an ordinary chart replay. This will provide the fastest and most efficient replay. There is no reason to use Accurate Trading System Back Test Mode."

The other three modes exist for automated systems. Calculate Same as Real Time recalculates studies on the Chart Update Interval. Accurate Trading System Back Test Mode is the heavy one with the freeze warning attached. Calculate at Every Tick/Trade matches it but recalculates the chart's studies for every data record in the Intraday file, which Sierra Chart calls "a very high accuracy, but inefficient, Back Test".

One timing rule: "The Replay Mode can only be set when a replay is started from a completely stopped state. Any changes to this setting after the replay is started, do not go into effect."

Can you replay market depth or a Trade DOM in Sierra Chart?

Only depth that was recorded before the period you want to replay. Sierra Chart documents three ways to have it: run the Market Depth Historical Graph study on a chart, in which case "the Market Depth data is automatically stored"; download it historically; or force it per symbol with Record Market Depth Data set to Yes.

The download route is narrow: "The downloading of historical market depth data is only supported with certain exchanges (CME, CBOT, NYMEX, COMEX, EUREX, CFE, NYSE, NASDAQ, AMEX) and only when using the Denali Exchange Data Feed or the Delayed Exchange Data Feed." Those nine venues are futures and equities exchanges.

The stored resolution is coarse, and the paragraph that says so also qualifies what you see: "A full snapshot of market depth is recorded once every 10 minutes. At the time you start a replay which includes market depth data, you will not necessarily see all of the market depth levels at that moment. It can take a few seconds or a minute or so to for them to fill in. Although the levels which are displayed are 100% accurate."

Can you take trades during a Sierra Chart replay?

Yes, and you do not switch anything on: "When replaying a chart, Sierra Chart will be placed into Trade Simulation Mode since this is required." Their line on support is plain: "Trade Simulation Mode is fully supported when Intraday charts are replayed."

The pricing page lists a Simulated Trading Service with every package, described as "unlimited simulated trading, using real time or delayed data using a server-based environment". The trade simulation page then rules that same service out for this job: it provides account balance tracking, "However, that service cannot be used during chart replays." So the included service with balance tracking is the one you cannot use in a replay.

The housekeeping rule matters if you re-run a day. The Clear Trade Data prompt is not optional in practice: "This is why it is important, to always clear the prior Trade Activity when starting a replay." Leave old fills in place and "both the prior order fills and any new order fills during the latest replay will be combined together giving you an incorrect Position Quantity after the replay is finished."

Their worked fill example uses gold: "[Sim]XAUUSD Trade simulation fill. Bid: 1071.90 Ask: 1072.40 Last: 1072.15".

How realistic are the fills during a Sierra Chart replay?

It depends on whether your data file holds real recorded bid and ask prices or estimated ones.

Method 1 uses what the market actually did: "the actual Bid and Ask prices during a replay are set to what they actually were during the real-time trading. This data is available from June 23, 2014 when using newer versions of Sierra Chart." It needs the Intraday Data Storage Time Unit set to 1 Tick and a one-off re-download per symbol. The backtesting page gives the same start date for historical bid and ask prices.

Method 2 estimates them, and the result is deterministic rather than realistic: "The Bid and Ask will always be 1 tick apart." The prices come from the High, Low and Close of the underlying records, processed in an order set by where the close sits: "The Low is processed first if the Close is closer to the High compared to Low, or the High is processed first if the Close is closer to the Low compared to the High." The backtesting page states the same rule for bar based tests and adds the tie-break, that the High goes first when the close is an equal distance from both.

Sierra Chart's own verdict on Method 2: "When the Bid and Ask prices need to be estimated, the actual values will not represent what they necessarily were in real-time. Therefore, trade simulation results during a replay will differ compared to actual live market conditions."

Three further limits are stated outright. Quote sizes are fictional, "the Bid Size and Ask Size values will always be 1 within the chart during a replay", unless market depth data is being replayed. Queue position is not modelled, because Estimated Position in Queue Tracking "only applies to non-replaying charts". And the fill time is the bar rather than the moment: "During a chart replay the timestamp of the fill will be based upon the ending time of the most recent chart bar, which is building at the time of the fill."

The order rules themselves are precise. "A Buy market order will be filled at the Ask price. A Sell market order will be filled at the Bid price." A buy limit fills "when the Ask price is equal to or less than the limit price". A buy stop fills at the ask once the last trade price reaches or passes the stop price, except where bid and ask are both above the last trade price, in which case it fills at the last trade price plus one tick.

Spread is handled through the instrument rather than through a cost setting. Sierra Chart's section on increasing the spread between bid and ask tells you to change the Tick Size: "If you make it twice the actual Tick Size, then this will result in the Bid and Ask being 2 ticks apart", and the same page notes that "it is not possible to have invalid Bid and Ask data during replays unless the Tick Size setting in Chart >> Chart Settings is wrong."

ChartLabs treats trading costs as their own settings. Commission and slippage are set per symbol, every trade's P&L, balances and analytics reflect them, and a Trading Costs card reports total costs, cost drag and average cost per trade. Why a tested result and a live result drift apart at all is the subject of Backtesting Accuracy: How Slippage and Data Quality Matter.

What can a Sierra Chart replay not do?

Daily and higher timeframes cannot be replayed as Historical charts: "It is not possible to replay Historical Daily, Weekly, Monthly and Yearly charts which are opened with File >> Find Symbol >> Open Historical Chart". The documented way round it takes seven steps: open an Intraday chart, set Chart Data Type to Intraday Chart Only, set the Bar Period Type to Days-Minutes-Seconds, set the value to 1-0-0 for daily bars or 7-0-0 for weekly, set the Start Time and End Time, press OK, then replay as normal.

You cannot trade over ground you have already covered. Jump back in time and you must not trade again across the period you jumped over: "trading again over the timeframe that you have jumped back over, inherently is just not supported unless you clear the order fills first."

Sierra Chart's own limit on what any of it proves: "back testing does not give results which will be exactly what you receive in real-time. This is not possible for various reasons. The actual bid and ask prices are not known and it is not known where in the order queue your order exists." On the backtesting page: "this does not mean that back testing will match real-time auto trade system evaluation. It will not."

Does a Sierra Chart replay cost anything?

Replay is not a separate line on the pricing page. What you pay for is a service package: Package 3 is "26 USD/month", Package 5 and Package 10 are "36 USD/month", Package 11 is "46 USD/month" and Package 12 is "56 USD/month", with a discount table that prices twelve months of Package 3 at 202.8 USD.

One part of replay does change the price. Replaying market depth needs the depth stored first, and the study that stores it automatically, the Market Depth Historical Graph, is listed under Advanced Features in Package 5 and Package 11, with Package 12 carrying the same features as Package 11 plus Market by Order. So the automatic depth-recording route starts at 36 USD/month rather than 26.

Two things come with every package: the "Sierra Chart Real-time and Historical Forex/CFD Data Service", and the Simulated Trading Service, the one that cannot be used during a replay. The pricing page also names a cost on futures data that sits outside the subscription, and it is exchange fees rather than spread or commission: "In the case of futures data, whether you use a Trading service for the market data, an external Data service, or the Denali Exchange Data Feed ..., you will have to pay exchange fees."

ChartLabs is one plan at $20 a month or $200 a year, with a 7-day free trial.

Is replaying a chart the same thing as backtesting?

On Sierra Chart's own pages, no. The page about back testing is titled Auto Trade System Back Testing, and a back test there is something a program does: either a Bar Based Back Test off the bars, which is "faster compared to a Replay Back Test, however it is less precise", or a Replay Back Test off the intraday file, "a slower method of back testing compared to a Bar Based Back Test, however it is more precise".

The word Manual in one of its section headings does not mean a human is trading. The section defines itself as "used when you want to run the Back Test at a slower speed to observe what it is doing", and its steps include, "Make sure there is a check mark by both Trade >> Auto Trading Enabled - Global and Trade >> Auto Trading Enabled - Chart ... Otherwise, the automated trading system will not generate any trades." Manual there means you drive the replay by hand while the program still places the trades. The route for a person taking the trades themselves is Chart Replay plus Trade Simulation Mode, documented on a different page. If the distinction matters to you, Manual vs Automated Backtesting covers what each one actually tests.

Sierra Chart replay and ChartLabs, side by side

Facts in each column come from that tool's own pages.

	Sierra Chart	ChartLabs
What can be replayed	Intraday scid data only; daily bars need an Intraday chart reconfigured in seven steps	Daily timeframes replay, and you can change timeframe during playback
Starting at a chosen date	One setting, Use Start Date-Time, which their own page says never to use; the supported route is to scroll back or press Home	Pick dates by length and period, or hand-pick a range, when you set up the session
Bars built on price rather than the clock	Range, Reversal, Renko, Volume and Point and Figure bars are among the variable timeframe bar types the replay instructions name	Range bars close after a fixed range, with entries and exits filled at the exact tick that crossed your level, currently on NAS100
Trading costs in the result	The documented spread control is the Tick Size setting, and estimated bid and ask are always 1 tick apart	Per-symbol commission and slippage feed P&L, balances and analytics
Markets	Forex and CFD data with every package; the depth download covers nine futures and equities venues	Forex, indices, commodities and crypto, with asset-class filters in the symbol pickers
Price	26 to 56 USD a month by package	One plan, $20 a month or $200 a year

Next step

If what you want is to replay a chart bar by bar and take practice trades without configuring a data file first, start with Forex Backtesting: Test Your Strategy on Real Data, then try it on your own strategy with a free trial.