CSTL

Castle Biosciences, Inc.

NASDAQ · Common stock

31.96

−1.84 (−5.44%)

Close, Oct 16, 2026

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Structural summary

What is the structure, what changed, and what would invalidate it

Viridia Intelligence

Context across dimensions, not a rating

StructureExpanding rangeIntermediate-degree swings on the daily chart.

WaveUnresolvedZigzag, wave C down (Pattern Confidence 71); the weekly count points the other way.

FibonacciZone belowNearest confluence 30.23–30.97 (3 relationships), −4.3% from the close.

MomentumStrong3 months +33.8% (ahead of SPY by 30.9 points); 6 months +27.6%.

RegimeMixed−4.7% vs the 50-day average, +11.1% vs the 200-day.

RiskNormal20-day volatility 48% vs 57% over the year; 1-year drawdown −57.8%; beta 0.87.

CSTL setup historyNot replayed yet; the track record fills in most-traded securities first.

Current structure

Price, swings and the preferred count on the chart

CSTL · 1DLoading bars…

SourceMassive, end of dayUpdated—MethodDaily bars, split-adjusted

Candidate interpretations

Every count shown passes every hard rule

Candidate interpretations

Ranked by Pattern Confidence

Counts ending at the latest intermediate swing high, 37.99 on Oct 6, 2026. 74 labelings tested, 57 broke a hard rule, 12+ remain.

Hard-rule evidence: why 57 labelings were eliminated

33Wave 2 always retraces less than 100% of wave 1
7Contracting triangle: C ends short of A's end, D short of B's end, and E short of C's end
6Wave 3 always travels beyond the end of wave 1
6Wave 4 always retraces less than 100% of wave 3
3Wave B ends short of the start of wave A (a zigzag is a sharp correction)
2Wave B retraces at least 90% of wave A

Method Every chain of 3–6 alternating pivots ending at the latest confirmed pivot is tested as each pattern; only counts with zero hard-rule failures are kept, then ranked by Pattern Confidence. Rules: rulebook.Engine pivots-1.0.0+rules-1.0.0+candidates-1.0.0+fib-1.0.1+rank-1.1.0+setup-1.0.1, bars to Oct 16, 2026

Fibonacci map

Confluence zones above and below the closeClose 31.96

31.96close

Bar length is the zone's strength (a weighted count of relationships, not a probability). Select a zone to see what forms it.

30.23 – 30.97−4.3% from the close

3 relationships · strength 2.2 · Intermediate, Minor degrees

30.97ProjectionWave C = 161.8% of wave A · Minor · Essentials · secondary ratio
30.25Swing38.2% retracement of the rise 2026-05-14 → 2026-10-06 · Intermediate · Basics
30.23RetracementCorrection retraces 50% of waves 1–5 · Minor · Basics · secondary ratio

Method Targets come from the Fibonacci relationships the sources describe for the wave in progress, Elliott trend channels, the prior fourth wave of lesser degree, and 38.2–78.6% retracements of the latest swing. A zone is where two or more independent relationships fall within max(¼ ATR, 0.4%) of each other; strength counts them, weighting primary ratios and higher degrees. It is not a probability.

Evidence

The setup the preferred count implies, and how that kind of setup has done

Setup

Intermediate degree · from the preferred count

The intermediate-degree scenario was held back

Its levels didn't pass Viridia's checks: invalidation over 25% away. It's listed for review instead of shown.

NoteResearch scenario generated from Viridia's structural model. Not a recommendation.MethodA setup restates the preferred count as a trade: the entry (the close, or the level where the correction in progress most often ends), the stop where the count is wrong (a rule level, or the end of a finished pattern), and the count's own Fibonacci target. Reward:risk is measured from the middle of the entry range. A setup needs reward:risk of at least 1 : 1. It is research output from the wave count, not a recommendation or a forecast.

Engine details

Analysis engine: pivots-1.0.0+rules-1.0.0+candidates-1.0.0+fib-1.0.1+rank-1.1.0+setup-1.0.1
Bars analysed to: Oct 16, 2026
Price history: Automatic, updated nightly
Daily bars: 514 since Sep 30, 2024
Avg volume, 50 days: 356.1K
Dollar volume, 20 days: $12.7M
SEC CIK: 0001447362
Provider symbols: nasdaqtrader: CSTL · massive: CSTL
Listing changes: None since Sep 24, 2026

SourcePrices: Massive (end of day, split-adjusted). Listings: Nasdaq Trader, SECUpdatedOct 20, 2026, 8:00 AM EDTMethodSecurity master, daily snapshot diff

MethodStructure: the intermediate-degree swing structure (higher highs and lows, lower highs and lows, expanding or contracting). Wave: the preferred daily wave count's expected direction (constructive up, defensive down), unresolved when the alternate is within 5 points. Fibonacci: the nearest confluence zone of Fibonacci relationships and the distance to it (inside, or within 3%, counts as at a zone). Regime: price against its 50- and 200-day averages. Momentum: 3-month return and its lead over SPY (strong when both are positive and the lead is over 5 points; weak when both are negative). Risk: 20-day volatility against the 1-year level (elevated above 1.25×), and the 1-year drawdown and beta to SPY.

Structure at a glance

Daily chart, as of Oct 16, 2026

Since the count's last pivot (37.99, Oct 6, 2026) price has moved −15.9%, the way the count expects.12 of 12 rule-valid counts expect the current move to be down.Weekly count: triangle wave C ↑, opposite direction

Close call.The top two counts are within 4 points. Treat the structure as unresolved until one is invalidated.

Preferred count

Zigzag down · wave C ↓

Price is in wave C of a three-wave zigzag correction down.

A-B from 44.28, Jan 26, 2026

Pattern Confidence71High

3 of 3 checks met

Key levels, preferred count

Invalidation+38.5% from close

44.28

Price above this level breaks the count.

Target, wave C−64.2% from close

11.43

Wave C = 100% of wave A

Nearest confluence zone−4.3% from close

30.23–30.97

3 Fibonacci relationships meet here.

Alternate count

Impulse down · wave 3 ↓

Price is in wave 3 of a five-wave decline (impulse).

1-2 from 44.28, Jan 26, 2026

Pattern Confidence67Medium

2 of 2 checks met

Why this count is preferred · 3 met, 0 not met

Met

Wave B retraces 38.2% to 85.4% of wave A
Wave B retraces under 90% of wave A (deeper B waves fit a flat better)
The count starts at the price extreme of the prior swing (a new trend begins where the old one ended)

Not met

None.

MethodPattern Confidence = (guidelines met + 2) ÷ (guidelines measured + 4), from the rulebook's guidelines, Fibonacci tendencies and wave-personality checks (wave 3 speed and volume, wave 5 volume, alternation in time, a start at the prior extreme), alternate waves in Fibonacci ratio, and the rarity of running flats. The alternate is the best-ranked count that tells a different story. It ranks the rule-valid counts against each other; it is not a probability of any outcome.

What changed

Structural events, most recent first

Oct 16, 2026Trend changedTrend moved from uptrend to mixed.
Oct 16, 2026New Fib zoneA new Fibonacci confluence zone formed near 30.6.
Oct 15, 2026Trend changedTrend moved from mixed to uptrend.
Oct 15, 2026New leading countNew leading count: Zigzag wC ↓ (confidence 71).
Oct 15, 2026Structure changedIntermediate structure changed from lower highs and lows to expanding.
Oct 15, 2026Count droppedTriangle wC ↑ is no longer among the leading counts; now Zigzag wC ↓.
Oct 15, 2026Daily/weekly alignmentDaily (down) and weekly (up) counts no longer agree.
Oct 15, 2026Swing confirmedA new intermediate swing high was confirmed.
Oct 12, 2026Trend changedTrend moved from uptrend to mixed.
Oct 12, 2026New Fib zoneA new Fibonacci confluence zone formed near 31.75.
Oct 7, 2026New Fib zoneA new Fibonacci confluence zone formed near 31.85.
Oct 5, 2026New Fib zoneA new Fibonacci confluence zone formed near 38.41.

Last swing high

37.99

Oct 6, 2026

Last swing low

17.72

May 14, 2026

Elliott Wave

Wave counts are built on these swings and each one passes every rule in the rulebook. They are ranked by how many guidelines they satisfy; the preferred and alternate counts are summarized above the chart.

MethodPrice versus its 50- and 200-day averages: above both with the 50 above the 200 is an uptrend, below both with the 50 below the 200 is a downtrend, anything else is mixed. Swings: adaptive ZigZag on daily bars, pivots-1.0.0+rules-1.0.0+candidates-1.0.0+fib-1.0.1+rank-1.1.0+setup-1.0.1.