Why “it looks stretched, I should take profits” is historically the wrong call on average, and only when near the one-year high
There is a moment every investor knows. A holding you have owned patiently runs hard for a few weeks and the markers are showing on the price chart. The chart starts to look vertical. Something in you says: this has got ahead of itself, take the money.
We put that instinct through a test. On the Stock Details tab in Signal Savvy Investor, the price history chart carries markers showing when a stock has moved unusually far from its own recent trading range. We took every one of those markers across the ASX (2,470 tickers, 2017 to 2026, roughly half a million marker days) and checked what the price actually did afterwards, over horizons from a single day out to a full year.
The short answer: if the stock was already near its one-year high, taking profits because the move looked stretched was historically the wrong call. Those stocks went on to beat the market by around 4% over the following year.
The longer answer is more interesting, and comes with a caveat we think matters more than the headline.
What the markers actually measure
Each marker answers one narrow question: how unusual is today’s closing price compared with this stock’s own trading range over the past three months?
We measure that gap in standard deviations — the statistician’s way of saying “how far outside normal”. A marker only appears once the price is at least two standard deviations out, which is genuinely uncommon.
| Marker | Meaning |
| Well above typical range | 2–3 standard deviations above the three-month average |
| Far above typical range | 3 or more above |
| Well below typical range | 2–3 standard deviations below |
| Far below typical range | 3 or more below |
These are descriptions, not forecasts. “Well above typical range” is a statement of fact about where the price sits, like observing that someone is unusually tall. Whether that fact predicts anything was the question we set out to answer.
The main finding: context decides what a marker means
Two identical markers can mean opposite things. What separates them is where the stock sits relative to its own one-year high.
| The situation | What happened next |
| Above its normal range, already near its one-year high | Beat the market by about 4% over the following year |
| The same, for the most extreme markers | About 7% |
| Above its normal range, but still far below its one-year high | Lagged by 2–4% over one to six months |
| Below its normal range, near its one-year high | Lagged by about 2% over the following year |
In plain English: a stock breaking higher when it is already strong is confirming that strength. A stock jumping while still deep in a hole is a bounce that fades.
The mirror image matters just as much. A dip below the normal range in a stock trading near its highs is not the bargain it appears to be. That is the one place our data actively argues against “buy the dip”.
The marker doesn’t tell you where a stock is going. It tells you whether the move you’re looking at is confirming strength or bouncing in a hole, and those look identical on the chart.
What a 4% average actually looks like
Here is the caveat.
About 35% of stocks carrying the marker beat the market over the following year, against 30% of stocks without it. That is a real improvement in the odds. It is also still a minority.
Most of the 4% comes from the marker group occasionally catching a very large winner, not from the typical stock in it doing better. Strip out the best 5% of outcomes from both groups and the gap shrinks from roughly 4 points to under 2.
Where this is genuinely useful
1. As a long-term tilt. If you are already inclined to hold or add to a stock trading near its one-year high, a well above typical range marker is mild historical support for that view rather than a warning sign. Four percent a year is not a strategy. Over a multi-year holding period it is worth having. Unlike a short-term edge, it does not have to clear a dealing cost every week.
2. As a tiebreak on a decision already made. Over five days the marker is worth about 0.2%, and an ASX round trip costs roughly 0.2–0.4%. As a standalone trading rule that plainly does not work. But if you were transacting anyway, the spread is already being paid, so a fraction of a percent on the timing is free.
3. As a check on your instincts about a fallen stock. If a stock sits well below its one-year high, the marker will not tell you it is cheap.
What the markers cannot do
- On their own, they predict nothing over investing horizons. Across the whole market with no context, neither the above nor the below marker beats the market by an amount distinguishable from luck. The context is doing the work.
- They say nothing about whether the company is any good. That is what earnings, balance sheets and our fundamentals tooling are for.
- Any single case will be swamped by news. These are averages across tens of thousands of observations. An individual stock can and will do anything.
- Consecutive markers are not accumulating evidence. A run of similar readings on consecutive days is one price condition persisting, not a series of independent confirmations.
The honest bottom line
Most charting tools will happily draw an indicator on every second candle and leave you to work out what it means. We would rather draw fewer, tell you exactly what each one measures, publish the horizon at which it works and the horizon at which it does not.
The marker is not a buy signal or a sell signal. It is one piece of context on a decision you are already making and, importantly, one that changes meaning depending on where the stock sits against its own highs.
If you would like to explore the Platform further, follow this link.
Based on the full ASX universe, 2017–2026, with company accounts going back decades. One market and one stretch of time. Trading costs are estimated from typical ASX spreads rather than measured from real fills. The valuation analysis excludes companies taken over during the period. Thresholds were chosen because they are easy to explain, not tuned for the best-looking result. Past patterns are not guarantees, and nothing here is personal financial advice.
