Market Basics · Chart Academy · Moving averages · Updated 2026-08-30
Moving averages, slope and stack
SMA versus EMA, why slope and stack beat crossovers, and why 5/20/60/120/240 and 20/50/100/200 are both correct.
이동평균선, 기울기와 정배열 — 단순이동평균과 지수이동평균, 골든크로스보다 기울기와 배열이 중요한 이유, 그리고 5/20/60/120/240과 20/50/100/200이 모두 맞는 이유.
What it is
A moving average smooths price over a chosen window. A simple moving average weights every bar in that window equally; an exponential moving average weights recent bars more heavily and therefore turns faster. Both lag price — that is what smoothing means, and it is not a defect to be engineered away.
How to spot it
Read three things, in this order: the slope of each average, where price sits relative to them, and how the averages are stacked against each other. A rising 20 above a rising 60 above a rising 120 describes a trend far better than any single crossover headline.
Period conventions differ by market, and both are legitimate:
- Korea — 5 / 20 / 60 / 120 / 240 (sometimes 250) are the common references.
- Global and US — 20 / 50 / 100 / 200 are the common references.
- GMR stores periods as configuration rather than hard-wiring one market's convention into core analytics.
Why people watch it
Moving averages give a fast read on trend regime and often act as dynamic areas of reaction. The 'golden cross' — commonly 50 over 200 in US discussion — and its inverse the 'death cross' are widely reported, which is itself a reason to know them even though the crossover is a lagging, whipsaw-prone event.
Because these crossovers are so widely reported, they sometimes matter for a reason that has nothing to do with the mathematics: enough people watch them that the headline itself becomes part of the day's news flow. That is worth knowing as media context, not as evidence about the chart.
Confirmation
A moving-average read is confirmed by agreement between slope, stack and price location, and ideally by structure that says the same thing. One crossover on its own is a headline, not a confirmation.
Invalidation
The stack compressing and losing order, or price cutting repeatedly back and forth through the averages, invalidates a trend read. Flat, tangled moving averages usually mean 'range' — which the structure lesson would already have told you.
Common mistakes
- Treating a golden cross as a buy event rather than a lagging description of something that already happened.
- Assuming the US 50/200 convention is universal and reading a Korean chart with the wrong periods.
- Counting SMA, EMA and MACD as three independent confirmations when all three derive from the same price series.
- Expecting a moving average to act as exact support.
Quick check
1. Which is usually more informative than a single crossover?
- The colour of the moving average
- Slope and stack read together with price location
- The exact crossover price
- The number of averages plotted
Show answer
B. Slope and stack read together with price location
A crossover is one lagging moment. Slope and stack describe the regime that produced it.
2. A Korean investor and a US investor use different moving-average periods. Who is right?
- The US convention, it is standard
- The Korean convention, it is more granular
- Both — the periods are conventions, and GMR stores them as configuration
- Neither, only EMAs matter
Show answer
C. Both — the periods are conventions, and GMR stores them as configuration
5/20/60/120/240 and 20/50/100/200 are both established. Hard-wiring one into core analytics would quietly make the product wrong for half its audience.
3. Why do SMA, EMA and MACD not count as three independent confirmations?
- They are calculated on different assets
- They all derive from the same price series, so they are correlated by construction
- MACD is not an indicator
- They use different timeframes
Show answer
B. They all derive from the same price series, so they are correlated by construction
Confluence means independent evidence agreeing. Three views of the same trend is one piece of evidence wearing three hats.