A cross in the extreme zone is stronger than merely reaching it.
The short answer
- What is the Stochastic Oscillator (Stochastic Oscillator)?
- Stochastic: where the close sits in the window's range, K% and D%.
- When does the Stochastic Oscillator get it wrong?
- It produces many signals and needs a trend filter. See its current reading on platform symbols, at the last daily close, in the "Reading now" table on this page. See current reading →
Reading now
| Ticker | Value | Five sessions ago | Status |
|---|---|---|---|
| SPY | 85.14 | 87.06 | In the upper zone (above 80) |
| QQQ | 49.09 | 94.39 | Between 20 and 80 |
| IWM | 27.06 | 49.15 | Between 20 and 80 |
| DIA | 74.25 | 43.51 | Between 20 and 80 |
A description of where the number sits against its thresholds. It is not an entry or exit signal.
Indicator limit
It produces many signals and needs a trend filter.
Read it with
Simple Moving Average: its crossovers in the direction of the slope of DMA-50 are more reliable than those against it.
It answers: has the move stretched? Is momentum changing?
What it actually does
The stochastic oscillator measures where the close sits in the period's range: where price closed between the lowest and highest point it reached over a window (14 by convention), turned into a number from 0 to 100. The logic is simple: in an uptrend closes tend to sit near the top of the range, and in a downtrend near the bottom.
How it is read in practice
Two lines: a fast one (%K) and a slow one that is its average (%D). The common thresholds 80 and 20 read as overbought or oversold, not as an order. Its strongest use is a crossover of the two lines inside an extreme zone: the fast line crossing above the slow one below 20 carries more weight than a cross in the middle, because the selling has already run out.
How it differs from the Relative Strength Index
Both are oscillators between 0 and 100, and the difference is the input: the Relative Strength Index compares the size of gains with losses, while this one measures position within the range. So the second is faster, more sensitive and noisier, and suits ranges better than strong trends.
Hypothetical example
A stock in a sideways range for three weeks: every drop pushes the oscillator below 20 and then its two lines cross upward, and every rally does the reverse above 80. Four successful cycles end with a fifth when price breaks the range: the oscillator stays above 80 and does not come back. The range it served is over.
Where it errs and why
In a strong trend it sticks to one end for weeks, so anyone who traded its thresholds against the trend lost regularly. It is also the noisiest of the oscillators, so it needs smoothing or filtering by a trend-strength gate.
Read it with
Read it with trend strength as a gate that decides which reading applies, with volume at extreme crossovers, and with structural levels: a bounce off a reference low with a crossover below 20 is stronger than either alone.
Where to see it on the platform
The technical chart shows it below price on any symbol and timeframe, and the scanner terminal shows its reading in the symbol card.
