Curriculum·S203 Chart Literacy and Evidence·about 41 min
Oscillators
By the end of this lesson you can
- →Explain what a bounded oscillator measures, and why the bound is a property of the formula
- →Show why an oscillator must saturate in a sustained trend, and what that does to a threshold rule
- →Identify why divergence cannot be acted on at the moment it is identified
- →State what an oscillator can honestly contribute to a decision
Sophomore · enrolled learners
This lesson opens with The 70 and 30 thresholds, disowned by the discipline that teaches them.
- What happened
- The relative strength index is conventionally read as indicating an overbought condition above 70 and an oversold condition below 30, and this is how it is taught to beginners almost universally. Practitioner literature from the field's own professional bodies and educational publishers states plainly that the standard thresholds are unreliable in trending markets, that a healthy uptrend routinely produces readings above 70 while pullbacks stop well short of 30, and that acting on an overbought reading as a sell signal in a trending market is a common way retail traders lose money. Wilder, who introduced the indicator, distinguished its behavior in trending and ranging conditions. The usual remedy offered is to move the thresholds to 80 and 20 in trends, which requires knowing you are in one.
- The decision point
- This is not a case of a technique being oversold by outsiders. The discipline's own institutions state that the standard interpretation fails in the condition where the tool is most consulted, and the interpretation is still what almost every chart package prints by default and almost every introduction teaches. The proposed fix requires the regime classification that S203-04 established is only reliable in retrospect.
What you will be able to answer
- →What does a bounded oscillator measure?
- →Why must an oscillator saturate in a trend?
- →Why can divergence not be acted on when identified?
- →What does an oscillator honestly contribute?
Orientation and Year One are open: anyone can read them without an account. From Year Two onward the lessons are for enrolled learners, because progress through the later years only means anything if it is tracked against a record.
It is free. We do not sell the list and there is nothing to buy at the end of it.
Sources and review
- https://cmtassociation.org/chartadvisor/mastering-the-relative-strength-index-rsi-how-to-read-it-correctly/
- https://articles.stockcharts.com/article/stop-thinking-of-rsi-as-overbought-and-oversold/
- https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1467-6419.2007.00519.x
- https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2308659
Confidence low·Volatility low·Reviewed 2026-08-05·Owner unassigned
Contested
This lesson is marked low confidence because the rigorous evidence on oscillators specifically is thin. The saturation argument is arithmetic and is not in dispute; the claim that the standard thresholds fail in trends is well attested in practitioner literature including the field's own professional bodies, and has not been established by the kind of testing S203-03 and S203-07 report for other techniques.
Practitioner sources are used deliberately here rather than as a shortcut. The point being made is that the discipline's own institutions disown the standard interpretation, which requires citing those institutions. Do not substitute stronger-looking academic sources that do not actually address this claim.