Bar Replay: practise trading on past crypto charts

Hindsight is the hardest thing to switch off when you study a chart: once you know where the price went, every entry looks easy. Bar Replay puts you back at a past moment with the later bars hidden and reveals them one by one, so each decision rests only on what you could have known then. This guide shows how to start a replay, which speeds and timeframes you can use, including 10 and 30-second crypto bars, and how the replay account lets you place practice trades on the past. The Help Center has a short Bar Replay article.

What Bar Replay is for

Bar Replay is available from the Starter plan. Use it to rehearse how you read a setup, to test a rule of your own bar by bar, or to see how a strategy would have handled a volatile day before you risk money on the idea. Indicators and AlertaScript scripts keep calculating as the bars appear, so what you see is what you would have seen at the time. When a script is slow, the replay waits for it briefly and the Actual speed reading shows the real pace; the replay slows down rather than stops.

Start a replay, step by step

On the web or desktop

1. Open a chart, for example BTC/USDT, and pick the timeframe you want to practise on.
2. Press the Bar Replay button at the top of the chart. The replay bar appears with the hint Select a bar to start replay.
3. Click the bar where the replay should begin. Everything to its right disappears. The Select bar menu also offers Select date…, First available bar and Random bar.
4. Use Step forward and Step back, or Play to let the bars come on their own, and choose a Speed.
5. To stop, press the Bar Replay button again, close the replay bar with ✕, or press Real-time to jump back to the live chart.

On the phone

1. Tap ⋯ (Analysis centre) on the bottom bar and choose Bar Replay.
2. Drag the line to the bar where you want to start, then tap Start.
3. The replay controls appear as a strip on the chart; on the phone the speed goes up to 5x.

Speeds, timeframes and how far back you can go

At 1x the replay reveals one bar per second. The speed menu runs from 0.1x (one bar every 10 seconds) to 10x (ten bars a second), whatever the timeframe: at 1x a 1-hour chart also moves one bar per second. You can change the timeframe during a replay to look at the bigger picture, and the replay keeps its place in time.

From Starter, crypto charts also offer 10 and 30-second bars, which suit practising fast entries and exits. They are crypto-only: stock charts have no sub-minute bars. How far back a replay can start depends on your plan's history depth, counted in bars, so for short bars it is a matter of hours or days:

When the replay reaches the last bar it has, an End of history card offers Continue live or Stay, where the replay continues as new candles arrive.

Trading the replay

While a replay runs, the Trade switch on the replay bar opens a separate replay account. It is not your Alerta Practice account: nothing you do in a replay touches it, and Practice orders stand down while the replay is on, so an order can never land at a price the chart is not showing.

• The account starts with 100,000 USD, 1x leverage, a 0.04 % market-order fee and no fee on limit or stop orders. Replay account settings change these; saving starts a new replay account from the bar the replay is on.
• Buy and sell with Shift+B and Shift+S, or open the Order ticket (Shift+T) for Market, Limit or Stop orders with take profit and stop loss as a price or as % of entry.
• A market order fills at the close of the last bar you can see. Limit and stop orders, take profit and stop loss only start working from the next bar, so the account can never use a bar it has not revealed.
• Stepping back undoes the fills of the bars you step over. Report shows the trades, win rate and maximum drawdown once the first trade has filled.
• Leaving the replay with an open position asks first and then closes it at the last replay price.

Alerta Practice is the live counterpart: it trades current prices with a virtual 100,000 dollars and is part of the Pro and Elite plans. A sensible routine is to rehearse an idea in replay, then follow it on live prices in Practice before using real money. The Alerta Practice article explains its orders and panels.

Settings and habits that matter

• Hide the answer. Start from Random bar or a date you do not remember, so you are not trading a chart you already know.
• Use your real size and costs. Set the replay account to the size and fees you would really pay; otherwise the result flatters you.
• Write down the plan first. Mark entry, stop and target with the long and short position tools before you press Play.
• Slow down at decisions. Use 0.5x or step bar by bar around your entries; speed up only through quiet stretches.

Common mistakes

• Expecting real alerts to fire during a replay. While a replay is active, your real alerts ignore replayed prices, so a level you scroll through does not wake your phone.
• Mixing up the two accounts. Replay trades stay in the replay account; your Practice balance does not change.
• Judging by one session. A handful of replayed trades is too small a sample to say a method works.
• Forgetting the costs. A strategy that only wins without fees and slippage is not ready for live markets.

Method and limitations

This guide is based on the AlertaChart Help Center and on the replay code: the speed list, the replay account defaults and fill rules, and the plan limits in the product's tier table, read on 5 October 2026. The history figures are calculated from the plan limits (bars × bar length) and are upper bounds.

• Replayed fills are simulated: there is no order book, no queue and no slippage beyond what you set as fees, so real fills in fast markets can be worse.
• Inside a bar the replay assumes a path (the extreme nearer the open first) when it decides which order fills first; the real path may have been different.
• U.S. futures rules require advisers who show simulated results to warn that such results do not represent actual trading and benefit from hindsight (17 CFR § 4.41). The same caution applies to your own replay results.
• Bar Replay shows past data only; it does not tell you how the next bar will close.

Related guides and help

• Crypto price alerts: set-up and limits
• Technical alerts: RSI, MACD and more
• Plans: Free, Starter, Trader, Pro and Elite
• Plans and prices

Open the AlertaChart charts and start a replay →Starter