InternalsUpdated daily after close
McClellan Oscillator: Breadth Momentum (EMA19 − EMA39 of Net Advances)
The classic breadth-momentum gauge: the 19-day EMA of net advances minus the 39-day EMA, computed across ~5,600 US equities. Positive = participation accelerating; negative = decelerating. Zero-line crosses, extremes, and divergences against SPY are the signals — and a negative reading is one of the four Hindenburg Omen criteria.
Today's reading
As of market close on July 21, 2026, the McClellan Oscillator is -70.90 — short-term breadth (19-day EMA of net advances) is lagging intermediate breadth (39-day EMA) across roughly 5,600 US stocks. The oscillator rose 70.4 points from the prior session. The series runs from 2010 to present.
Sources, methodology & freshnessLast updated 2026-07-21 · Open ↓Close ↑
Source
Daily net advances across ~5,600 US equities (2010–present)
Methodology
EMA19 − EMA39 of raw net advances; EMAs SMA-seeded after a full warmup period
Updates
Daily after market close (~1:30 PM PT)Last: 2026-07-21
Maintained & reviewed by Yuriy Matso — methodology shown on the page.
Breadth momentum2026-07-21 · close
DECELERATING
-71
Short-term breadth is lagging intermediate breadth.
Oscillator
-70.90
Δ 1 Day
+70.4
Zero Line
below
SPY closed at $748.28. A negative oscillator is one of the four Hindenburg Omen criteria.
Range:
01
McClellan oscillator
McClellan Oscillator vs SPY
EMA19 − EMA39 of net advances, SPY overlaid. Broad-universe raw-net-advances variant — judge extremes against this series' own history (±300-400 marks stretch), not classic NYSE thresholds.
McClellan OscillatorSPY price (right)Zero line
Reading the current tape
As of 2026-07-21, the McClellan Oscillator stands at -70.90 — breadth momentum is negative (short-term participation decelerating), with SPY at $748.28. The oscillator rose 70.4 points on the session.
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How McClellan Oscillator Works
- 1Start from daily net advancesEach session we count advancing minus declining stocks across our ~5,600-symbol US equity universe — the same series that drives the advance-decline line.
- 2Smooth with two exponential moving averagesThe oscillator is the 19-day EMA of net advances minus the 39-day EMA. Both EMAs warm up over their full period (seeded with the SMA) before the oscillator prints, so early values are never seed-dominated.
- 3Read it as breadth momentumPositive = short-term breadth running ahead of intermediate breadth (acceleration); negative = deceleration. Zero-line crosses mark momentum regime changes; extremes mark exhaustion.
- 4Watch divergences and the zero lineA rising index with a falling oscillator means each push is coming on weaker participation. A deeply negative oscillator that turns up before price does is the classic early-bottom tell. The oscillator is also criterion #3 of the Hindenburg Omen (must be negative).
Who Uses McClellan Oscillator
Swing Traders
Time entries within trends: oscillator pullbacks to/below zero inside a healthy uptrend are reset points; the curl back up is the trigger.
Mean Reverters
Deep negative extremes mark short-term selling exhaustion; deep positive extremes after extended rallies flag chase risk.
Trend Followers
Use sustained time on one side of zero as a regime read: persistent positive readings characterize durable advances, persistent negative ones distribution phases.
Omen Watchers
The Hindenburg Omen requires a negative McClellan reading. Track it here to see how close the breadth-momentum leg of that signal is to flipping.
Pro Tips
01
Complex vs simple structures
The McClellans' own reading style: a "complex" bottom (multiple oscillator troughs below zero) carries more durable-low information than a single V-shaped dip. Same for tops in mirror image.
02
Divergence at the extremes is the strongest form
Price making a lower low while the oscillator makes a higher low (still negative) is the textbook positive divergence — breadth momentum improving before price.
03
Mind the scale of our variant
We compute raw net advances over ~5,600 issues, so amplitudes run larger than the classic NYSE ratio-adjusted oscillator (±100 there ≈ ±300-400 here). Compare readings to this chart's own history, not to NYSE-based thresholds.
04
Pair with the A-D line
The oscillator is the momentum of the A-D line. Oscillator says "how fast breadth is changing"; the cumulative line says "where breadth stands". Signals agreeing across both are the high-conviction ones.
Common Issues & Solutions
Your values differ from StockCharts / the McClellan Financial site▾
Variant differences: the classic oscillator uses NYSE-only issues and often ratio-adjusted net advances (net advances ÷ total issues). Ours uses raw net advances across ~5,600 US equities — larger amplitude, same shape and timing. Read levels against this series' own history.
The oscillator whipsaws around zero▾
Normal in range-bound tape — breadth momentum genuinely flips frequently when the market chops. The zero-cross signal works best when it confirms a breakout or follows an extreme; standalone crosses in quiet ranges are noise.
Where is the Summation Index?▾
The McClellan Summation Index (the running total of the oscillator) isn't built yet. The cumulative A-D line on our advance-decline page covers similar slow-trend ground in the meantime.
Frequently Asked Questions
What is the McClellan Oscillator?▾
A breadth-momentum indicator developed by Sherman and Marian McClellan in 1969: the 19-day EMA of net advances (advancing minus declining stocks) minus the 39-day EMA. Positive readings mean short-term breadth is outrunning intermediate breadth — participation accelerating; negative readings the reverse.
How do I read the zero line?▾
Zero crossings mark breadth-momentum regime changes. Crossing up through zero after a negative extreme is an early-recovery signal; persistent time below zero characterizes corrections and distribution phases. The Hindenburg Omen requires the oscillator to be negative as one of its conditions.
What counts as overbought or oversold?▾
For the classic NYSE ratio-adjusted oscillator, ±70 to ±100. Our variant uses raw net advances over ~5,600 issues, so amplitudes are larger — judge extremes against this chart's own history (roughly ±300-400 marks comparable stretch). Extremes flag exhaustion, but in fresh trends an extreme can also mark initiation thrust — context matters.
What is a McClellan divergence?▾
Price and the oscillator disagreeing at the swing: index lower low + oscillator higher low = positive divergence (breadth momentum improving first, common at bottoms); index higher high + oscillator lower high = negative divergence (advance narrowing, common before corrections).
How is this related to the Summation Index?▾
The McClellan Summation Index is the running cumulative total of the oscillator — a slower, position-style indicator built on the same engine. We don't publish it yet; the cumulative A-D line covers similar slow-trend territory.
What universe and parameters does this use?▾
Net advances across ~5,600 US common equities (2010–present), EMA19 − EMA39 with full-period SMA-seeded warmup, recomputed after every close. This is a broad-universe raw-net-advances variant, not the NYSE-only ratio-adjusted version.
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Last updated: 2026-07-21