Weekly Monitor · Learn

200-day moving average

the market’s long-term center of gravity · Price trend & timing — reading the chart

In plain English

Take the closing price for each of the last 200 trading days and average them. Do that every day and you get a slow, smooth line running under the jumpy daily price — where the stock has traded, on average, over roughly the past year.

What it tells you

Whether the long-term trend is up or down. Price above the 200-day line = an uptrend, buyers in control. Price below = a downtrend — and in this app’s own backtest, the single most reliable warning sign. Because it averages a year of prices, one bad day barely moves it, so it cuts through the daily noise that panics people.

Why 200 days

About 200 trading days ≈ one year. Long enough to ignore short-term wiggles, short enough to still turn when the real trend changes.

In this app

It’s the backbone of the Trend score and the rule the backtest said mattered most: never buy support in a downtrend. A name trading below its 200-day gets a REVIEW signal — the app makes you re-confirm the thesis before adding, instead of catching a falling knife.

The calculation
200-DMA = (P₁ + P₂ + … + P₂₀₀) ÷ 200
What each piece means
Pₙ
— the closing price n trading days ago (P₁ = yesterday, P₂₀₀ = ~a year ago)
÷ 200
— divide the sum by 200 to get the average
A worked example

A stock spends months climbing above a rising 200-day line (healthy uptrend), then breaks below it. Nothing about the daily price looks alarming, but the long-term trend has flipped — exactly the moment the app switches the name to REVIEW and asks you to re-check the story before adding more.

Dig deeper
See it run on live stocks →Weekly Monitor computes this on ~1,000 names — free, in your browser, every formula shown. Nothing here is advice.
← Analyst price target 50-day moving average & the golden cross →