ATLASStock probability: what is the chance a stock goes up this month?
For 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.
What it does
The probability answers one narrow question: will the price be above today's price in about a month? Next to it you get the middle outcome and two ranges, the middle 50% and a wide 90%, so you see how far the price might move either way.
A number like 54% is not a signal to buy. It tells you the stock has a slight tilt, and the range tells you whether that tilt matters compared with the stock's normal swings.
Worked example with live data
Real ATLAS numbers, prices as of Oct 26, 2026.
Live example: AAPL at $346.86 has a 53% chance of closing higher in 21 sessions. The middle outcome is $348.28, and nine times out of ten the price should land between $316 and $384. Across the four stocks below, chances run from 50% to 53%: the model rarely sounds certain.
How ATLAS calculates it
Starting from a stock's price, drift and volatility, ATLAS builds a distribution of the price in 21 sessions. The drift is the market's long-run return (about 7% a year) minus a volatility penalty that makes very volatile stocks rise less often; the volatility blends the recent 3-week level with the long-run level. The curve has fat tails, with parameters fitted separately for US, world and small-cap world stocks.
We kept this simple model because we tested the alternative. In a backtest of about 148,000 predictions, the short-term return signal did not beat a constant drift, while the calibrated ranges captured the right share of outcomes (50% range: 50-51%, 90% range: 89-91%).
Limits you should know
A shared shock, like April 2025's tariff week, moves almost every stock at once and no per-stock model foresees it. The probability says nothing about why a stock moves and is not a recommendation to buy or sell.
Where it sits in the plans
The probability appears on every public stock page. In the app, the Free plan covers the 200 largest US companies and funds, Starter and above cover all companies, and the ranked lists of the most likely movers are part of ATLAS PRO.
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Frequently asked questions
What is the probability that a stock goes up?
For a one-month horizon, most stocks sit fairly close to 50%. ATLAS shows the figure for each stock together with the range, so the number is not read in isolation.
How accurate are stock probability models?
ATLAS tests its ranges against past outcomes: its 50% range has held about 50-51% of the time and its 90% range 89-91%. Direction itself is hard to predict, so the probability stays near 50%.
What does 21 trading sessions mean?
It is the number of trading days in roughly one calendar month, so the probability refers to the price about a month from now.
Is a higher probability a reason to buy?
Not by itself. A 58% chance still means the stock falls 42 times out of 100, and the size of the move matters as much as the direction.
Related tools
- Monte Carlo simulationA Monte Carlo simulation runs thousands of random but realistic price paths and reads the outcomes as a distribution, so you see how wide the possibilities are instead of one guess.
- Recovery probabilityIf you bought above today's price, ATLAS estimates how likely the stock is to get back to your purchase price within a given time, and how long that usually takes.
- Track recordATLAS publishes how its past forecasts turned out. In testing on about 148,000 predictions, its 50% range held 50-51% of the time and its 90% range 89-91%.
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