In plain terms — An SOS is an advance that covers more ground on relatively greater activity. In the Wyckoff model it suggests demand is prevailing, but it only has meaning within an analysed trading range.
Definition
A Sign of Strength (SOS) is an advance with expanding price spread and relatively higher volume. It can be one wave or a sequence of bars. “Relatively” is essential: volume, range and progress are compared with earlier rallies and reactions in the same instrument and time frame.
In Wyckoff codification, the SOS often follows a spring and can support that interpretation; in phase D it shows progress toward or through the upper part of the range. It does not prove that demand has gained permanent control, nor does it require a close in an exact fraction of the bar.
SOS and Jump Across the Creek
Jump Across the Creek (JAC) is Robert Evans's metaphor for crossing the internal resistance area called the creek. An SOS can coincide with that jump, but the terms are not perfect synonyms: SOS describes the advance's price-volume quality, while JAC describes its position relative to resistance.
| Control question | Why it matters |
|---|---|
| Is an accumulation range already recognisable? | Avoids labelling every breakout an SOS |
| Do spread and volume expand relative to comparable waves? | Checks the effort-versus-result relationship |
| Does price retain part of the progress? | Immediate negation weakens the label |
| Is the following reaction more contained? |
Teaching example — After a test in the lower part of a range, price crosses internal resistance at 52 and reaches 55 on wider bars and more volume than earlier rallies. It is a candidate SOS/JAC. An orderly return toward 52–53 would strengthen the reading; an immediate deep return into the range would weaken it.
Limits and use
- A high-volume breakout can fail; volume is not self-sufficient confirmation.
- A prior spring is common, not compulsory.
- A later LPS may not appear or may occur more than once.
- This entry describes an analytical label; it does not prescribe an entry, stop or position size.
The bearish counterpart in distribution is the Sign of Weakness (SOW).
Sources
- Wyckoff Analytics — Wyckoff Method — SOS definition, phase D and its relationship with LPS.
- StockCharts ChartSchool — The Wyckoff Method: A Tutorial — spread, relative volume, spring and the back-up metaphor.
- Hank Pruden — The Wyckoff Method of Technical Analysis and Speculation, Wiley — discretionary judgement of price and volume.
These sources document the terminology and procedure; they do not validate a universal continuation probability after an SOS.
Wyckoff Analytics and StockCharts publish substantially the same tutorial: they are cited as two locations for the same codification, not as independent confirmations. The Wiley DOI page exposes the metadata and publication record; the full text may require a subscription or institutional access.