ATLASPaper trading: test every trade on real prices before risking money
Paper trading means placing practice trades with pretend money. ATLAS does it at real closing prices and shows the dollar risk of each trade before and after you place it.
What it does
Where the stock market simulator is about learning the whole game, paper trading is about rehearsing a specific trade. You decide the stock and the number of shares, place the order, and ATLAS tracks the position against real closes.
Two modes cover the two things people want to test. Today's market lets you try an idea now and leave pending orders that are checked at every new close. Time travel lets you test a decision from a past date and step forward, so you find out whether a habit, such as buying after a jump, would have worked.
Worked example with live data
Real ATLAS numbers, prices as of Oct 26, 2026.
Example: buying 10 shares of AAPL at $346.86 costs $3,469. On an ordinary day this position moves about $38 either way. In 21 sessions, 1 case in 20 is worse than a $311 loss (9% of the position).
| Measure | Value |
|---|---|
| Order | Buy 10 AAPL at $346.86 |
| Cost | $3,469 |
| Typical daily swing of this position | ± $38 |
| Likely range (middle 50%) | $3,362 – $3,608 |
| A bad month (1 in 20) | − $311 |
How ATLAS calculates it
The size of a trade is shown in the units that matter: dollars. ATLAS multiplies the stock's recent daily volatility by your position to show the swing you should expect on an ordinary day, then uses the calibrated one-month distribution to show the range of outcomes over 21 trading sessions.
The "bad month" line is the 5th percentile of that distribution: about one month in twenty should be worse. It is a planning number, not a floor. Gaps from earnings or news can break through it, which is why the model uses fat-tailed distributions rather than a bell curve.
Limits you should know
Fills happen at the daily close, so slippage, spreads and partial fills are not modeled. Paper results flatter the trader: it is easier to hold through a drop that costs nothing.
Where it sits in the plans
Paper trading is available on every plan. Free keeps up to 10 positions; Starter and above remove that cap.
Run it on your own numbers
Create an account to use this tool with your stocks, your amounts and your horizon.
Get started →Plans from €3.99 a month.
Frequently asked questions
What is paper trading?
Paper trading is practicing buying and selling with pretend money at real market prices, so you can test a strategy without financial risk.
Is paper trading the same as a stock market simulator?
They overlap. In ATLAS the simulator is the whole learning environment, while paper trading focuses on single trades: how many shares, how much can I lose, and how did that decision play out.
Does paper trading use real-time prices?
ATLAS fills practice orders at real daily closing prices, not live ticks. That is enough to test ideas that play out over days and weeks, but not day-trading timing.
How long should I paper trade before investing real money?
There is no fixed rule. A useful test is to run through at least one falling month and see whether you follow your own plan when your balance drops.
Related tools
- Stock market simulatorThe ATLAS stock market simulator gives you $10,000 of virtual cash to invest at real market prices, so you can learn how positions behave without risking real money.
- Price alertsATLAS price alerts tell you when something changes in your stocks, and the probability of touching a price level helps you choose levels that will actually fire.
- Stock probabilityFor any stock, ATLAS estimates the probability that it closes higher in 21 trading sessions (about one month) and the range where it should land. Most answers sit close to a coin flip, and that is the honest result.
Stocks used in this example
Open any of them to see the full public page, with fair value, odds and a one-year chart:
Not investment advice. ATLAS estimates come from statistical models and public data; they can be wrong and past results do not predict future ones. Disclaimer