Sim Street
Balance—

BTC

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Balance—

Drag the chart to look back. Scroll to zoom.

Connecting to live prices…

Your account

How you're doing

Free to trade with
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In your open trade
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Sim Dollars bought
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Pro top-ups
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Overall result
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Trades you won
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Best trade
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Worst trade
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Fees paid
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Past trades

Terms · Privacy · Support

Plans

Free

$0 for as long as you like
  • Live prices on every coin traded on both Binance and Coinbase, hundreds of them
  • Candles down to 5 seconds
  • Trend signal, Volume, Bollinger Bands and RSI
  • Your account synced across devices once you sign in
  • $1,000 to start; buy more if you run out
  • Your last 300 closed trades kept
  • No scripts of your own

Pro Pro

$20 a monthor $40 for 3 months
  • Everything in Free
  • Topped back up to $10,000 every 8 hours, whenever you run low
  • Write your own indicators in JavaScript
  • Every closed trade kept, for as long as you like

Pro includes Sim Dollars: your account is topped back up to $10,000 every 8 hours. Anyone can also at any time. The pricing page has the full comparison and the questions people ask. Placeholder: the upgrade button switches your plan on this device and takes no payment; checkout, receipts and cancelling come with the backend.

Buy Sim Dollars

Ran low, or want to trade bigger? Top up your account. Sim Dollars stay play money: they can't be withdrawn or exchanged for anything, and nothing here pays out.

Free to trade with now—

Your scripts

Write a few lines of JavaScript and they're drawn on the chart like the built-in indicators: lines over the price or in a strip of their own, arrows on candles, and a plain-words reading at the top. Scripts are saved in this browser.

Pick a script on the left, or start a new one from a template. The Moving average cross template is a good first look: it draws two lines and marks where they cross.

Everything a script can use
candles, n
The candles on the chart, oldest first; n is how many. Each is { t, o, h, l, c, v }: time in milliseconds, open, high, low, close, and dollars traded. The newest is candles[n - 1].
closes() opens() highs() lows() volumes()
One number per candle, as a list the length of n.
sma(src, len) ema(src, len)
Simple and exponential moving averages of a list. Every helper gives back a list the same length as its input, with NaN where there isn't enough data yet.
rsi(src, len) stdev(src, len)
RSI and standard deviation over the last len values.
highest(src, len) lowest(src, len)
The highest or lowest of the last len values.
change(src, len = 1)
How much each value differs from the one len back.
cross(a, b)
1 where a crosses above b, -1 where it crosses below, 0 elsewhere.
plot(name, values, options)
Draws values (one per candle, or a single number) as a line. Options: color; pane: 'own' for a strip under the price instead of on it; style: 'line' | 'hist' | 'dots'; width; dash: [4, 3]; down, a second colour for histogram bars below zero. Up to 8 per script.
mark(i, text, options)
An arrow at candle i. Options: up: true (below the candle, pointing up) or false; color.
level(price, label, color)
A horizontal line at a price.
say(words)
What the reading means right now, in plain words, shown at the top of the chart.
coin, tfMs, price
The coin's symbol, the candle length in milliseconds, and the latest price.

It's ordinary JavaScript, so Math, loops and const all work. A script runs again whenever the chart gets a new price; one that takes longer than a quarter of a second is switched off so the chart stays smooth. Scripts summarise what the price has already done, like every indicator: none of them can see the future.