- What simple and exponential averages compute, and when the difference matters
- How to use an average as a trend filter rather than a signal
- The honest evidence on golden crosses, and what to use instead
A moving average contains no information that price does not. Its value is that it converts a noisy series into a single line whose level and slope are unambiguous — and unambiguous is worth a great deal when you are trying to write down rules you can follow.
The periods that matter, and why
- 10 / 20-day EMARepresents: Short-term momentumTypical use: Pullback entries in strong trends; trailing stops on fast movers
- 50-dayRepresents: Intermediate trendTypical use: The reference for swing positions; a widely watched dynamic level
- 150-day / 30-weekRepresents: Medium-term balanceTypical use: Stage analysis — the Weinstein average
- 200-dayRepresents: Primary trendTypical use: The single most-watched line in markets; bull/bear demarcation
Three legitimate uses
- 1As a trend definition. "Price above a rising 200-DMA" is a precise, testable state. It removes argument from the question of whether a trend exists, which is the whole point of the stage framework.
- 2As a dynamic level. In an established trend, pullbacks frequently find demand near the 20, 50 or 200-day average. This is behavioural clustering, and it varies enormously by instrument — some stocks respect their 200-DMA repeatedly, others ignore it entirely.
- 3As a filter, not a trigger. "Only take long setups when price is above the 200-DMA" is a robust use. "Buy when price crosses the 50-DMA" is not, because the average is by construction late.
Whether a moving average acts as support is not a universal fact — it is a property of the individual instrument, and it can be measured: what proportion of touches of the 200-day average produced a bounce rather than a break?
Our Chart DNA engine computes this per stock precisely because the variation is so wide. Assuming every chart respects its averages equally is one of the more common unexamined assumptions in technical work.
The golden cross, honestly
The 50-day crossing above the 200-day is called a golden cross; the reverse is a death cross. Both get substantial media coverage. Both are, mechanically, two lagging averages confirming what price did months ago.
A stock bottoms and begins advancing. Trace when each signal actually fires.
- Low
- ₹280day 0
- Structure turns (higher high + higher low)
- ₹316≈ day 25
- Price crosses above 200-DMA
- ₹352≈ day 55
- 200-DMA slope turns up
- ₹389≈ day 85
- Golden cross fires
- ₹404≈ day 100
It is tempting to test 43-day and 47-day averages and discover that one of them would have performed beautifully on the last two years. This is curve-fitting, and it does not survive contact with new data.
Two defences. Prefer round, widely used periods (20, 50, 200) precisely because their effect is partly behavioural — a period nobody watches has no behavioural component at all. And check that a result is not fragile: if 50 works and 45 and 55 don't, you have found noise.
- ✓"Only long setups while price is above a rising 200-DMA" — a filter
- ✓"Trail the stop under the 20-EMA in a fast trend" — an exit rule
- ✓Reading the slope to judge whether the balance is improving
- ✓Measuring extension: how far price is above the average
- ✕Buying every 50-DMA cross
- ✕Optimising the period against past data
- ✕Treating a golden cross as an entry
- ✕Assuming every stock respects its averages equally
- ✕Stacking six averages until one of them explains any move
- ☐Pick one type (SMA or EMA) and a small set of periods, then keep them.
- ☐Read the slope, not just the position of price relative to the line.
- ☐Use the long average as a permission filter, not as a trigger.
- ☐Measure how far price is above the average — extension is a real risk factor.
- ☐Check this specific stock's history of respecting the level before relying on it.
In one screen
- 1Moving averages add no information — they add unambiguous summary.
- 2The 200-day and 30-week matter analytically and because everyone watches them.
- 3Use long averages as filters and trend definitions; use structure for entries.
- 4Golden crosses confirm what price did months earlier — a regime statement, not a signal.
Check yourself
Nothing is scored or stored — the explanation after each answer is the point.
A stock's 50-DMA crosses above its 200-DMA after a 44% advance off the low. How should this be used?
Why prefer standard periods like 50 and 200 over an optimised 47 and 193?