Vyreon LabsMarket Measurements

Learn the measurements

RSI vs Stochastic Oscillator: What Each Measures and Why They Differ

RSI measures the balance of gains and losses; the stochastic shows the close's place in its range. Scales, 70/30 vs 80/20, and when the two disagree.

Reviewed · Sources at the end · How Vyreon measures
Vyreon's per-security reports are not live yet; this page describes what they will measure. Examples are illustrative.

RSI and the stochastic oscillator are both 0-to-100 momentum readings over 14 sessions, but they measure different things. RSI compares the size of recent up closes with recent down closes; the stochastic shows where today's close sits inside the recent high–low range. An up close raises both and a down close lowers both, all else equal; when they disagree, the difference describes the shape of recent trading.

What RSI Measures

RSI (Relative Strength Index) uses only closing prices. It averages the gains on up days and the losses on down days with Wilder smoothing, then compares them:

RS = average gain ÷ average loss, RSI = 100 − 100 ÷ (1 + RS)

Near 100 means recent closes have been almost all gains, near 0 almost all losses. Because of the smoothing, a large move stays in RSI for a while and fades gradually. See RSI.

What The Stochastic Oscillator Measures

The stochastic uses highs, lows and closes. Raw %K is the close's position within the range of the last 14 sessions:

%K = 100 × (close − lowest low) ÷ (highest high − lowest low)

The slow stochastic then averages raw %K over 3 sessions, and %D averages that over another 3. A reading of 100 means the close is at the top of the 14-session range, 0 at the bottom. See stochastic oscillator.

RSI Vs Stochastic: Scales And Conventions

RSI Slow stochastic
Input Close-to-close changes High, low, close
Measures Balance of gains and losses Position within the range
Scale 0–100 0–100
"Overbought" convention 70 and above 80 and above
"Oversold" convention 30 and below 20 and below
Lines One Two (%K and %D)

Both sets of thresholds are conventions. They describe how one-sided recent trading has been, not whether a price is right or wrong.

When RSI And Stochastic Disagree

  • A rebound after a sharp drop: a few up days can lift the close from the bottom of the range to the middle, so the stochastic jumps. RSI still carries the large earlier losses and rises more slowly.
  • A quiet drift near the top: after a strong rally, small mixed closes near the highs keep the stochastic high while RSI eases back toward 50, because gains and losses are now similar in size.
  • A narrow range: when the 14-session high and low are close together, small price changes swing the stochastic across its whole scale, while RSI barely moves.
  • A big day leaving the window: the stochastic range resets abruptly when an extreme high or low drops out. RSI's smoothing has no such edge.

Illustrative example: a stock falls 1.00 a session for ten sessions, from 110 to 100, then rises 1.00 a session for four, to 104. Taking each session's high and low as its close, the last 14 sessions run from 109 down to 100, so raw %K is 100 × 4 ÷ 9 ≈ 44. Over the same 14 changes the average gain is 4/14 and the average loss 10/14, so RS = 0.4 and RSI ≈ 28.6. RSI is "oversold by convention" while the stochastic sits mid-range.

Stochastic RSI combines the two ideas: it applies the stochastic formula to RSI itself, measuring where today's RSI sits in its own 14-session range.

How Vyreon Calculates Them

  • Wilder RSI(14) on closes adjusted for splits and dividends, with its 70/30 condition and a 252-session percentile.
  • Slow stochastic (14, 3, 3) and Stochastic RSI (14, 14, 3, 3) on adjusted daily bars.
  • Williams %R(14), the fast stochastic on a −100 to 0 scale.

What Neither Tells You

  • Both describe recent prices. Neither forecasts the next move.
  • Agreement is not confirmation; both are built from the same prices.
  • Thresholds and crossings are conventions, not rules.

Related: RSI · stochastic oscillator · Williams %R · MACD vs RSI · CCI

Sources

  • J. Welles Wilder Jr., New Concepts in Technical Trading Systems (1978): RSI and Wilder smoothing.
  • George C. Lane, credited with developing the stochastic oscillator and its %K and %D lines.
  • Tushar Chande and Stanley Kroll, The New Technical Trader (1994): introduced the Stochastic RSI.
  • Larry R. Williams, How I Made One Million Dollars Last Year Trading Commodities (1973): introduced %R.

The 70/30 and 80/20 levels are trading conventions; we know of no peer-reviewed source establishing them as thresholds.