Statistical Model

Hidden Markov Models (HMMs)

Know which phase of growth you’re in—before your dashboards make it obvious.

Hidden Markov Models answer a question leadership teams usually feel intuitively but can’t prove: “Are we growing, plateauing, or quietly sliding—and when did that change?”

The Problem This Model Solves

Most dashboards show what happened, not what state you’re in. Teams often react too late because growth slows gradually, early warning signals are noisy, and metrics contradict each other.

By the time ROAS, revenue, or CAC clearly worsen, the decision window has already closed.

Questions This Model Answers

"What growth regime are we currently in?"

"When did the regime shift actually occur?"

"Is this slowdown temporary or structural?"

"Are we scaling efficiently—or forcing growth?"

"Should budget strategy change right now?"

How the Model Thinks (Without the Math)

An HMM assumes the business operates in hidden states (regimes) that you don’t observe directly. You only see noisy signals (revenue, ROAS, CAC).

The model infers the most likely underlying state and estimates transition probabilities between them. Think of it as: “Reading the weather system, not just today’s temperature.”

Core Business Use Cases

1Early Growth Slowdown Detection

The Problem

Growth decelerates before KPIs collapse.

What It Reveals

A transition from expansion to saturation.

Decision Enabled

Adjust strategy before waste accumulates.

2Budget Strategy Shifts

The Problem

Scaling playbooks are applied too long.

What It Reveals

When aggressive scaling stops working.

Decision Enabled

Move from expansion to efficiency mode.

3Post-Campaign Reality Checks

The Problem

A big launch inflates short-term metrics.

What It Reveals

Whether the underlying regime actually changed.

Decision Enabled

Avoid mistaking spikes for structural improvement.

4Crisis & Recovery Monitoring

The Problem

External shocks distort performance.

What It Reveals

Temporary regime vs long-term damage.

Decision Enabled

Avoid overcorrecting during short-term turbulence.

5Leadership & Board Communication

The Problem

Explaining performance feels subjective.

What It Reveals

Objective regime classification with probabilities.

Decision Enabled

Align leadership on the right posture.

Powered by SpendSignal

How We Use This Model

SpendSignal uses HMMs as a meta-layer over all other models.

Specifically:

  • Growth regime classification (Growth / Plateau / Decline)
  • Regime-aware budget recommendations
  • Risk-adjusted forecasting
  • Inputs into the Growth Resilience Score

This prevents the most expensive mistake in marketing: applying the wrong strategy at the wrong time.

Example Output

Instead of “ROAS is down 8% MoM”, you see:

  • 78% probability: Saturation regime
  • Regime shift detected: 3 weeks ago
  • Recommended posture: Defend margin, reallocate spend

The insight: "This isn’t a bad week. It’s a different phase."

Works Best When

  • Multiple performance signals are available
  • The business has gone through cycles
  • Strategic timing matters more than tactics

Be Cautious When

  • Data history is extremely short
  • One-time launches dominate the signal
  • You need channel-level optimization (use GAMs)

Frequently Asked Questions

Is this predicting the future?

No. It infers the current underlying state from observed signals.

Can regimes revert?

Yes. HMMs explicitly model probabilities of transitioning both ways (e.g., Recovery → Growth).

Is this overkill for marketing?

Only if you enjoy reacting late.

Stop Guessing. Start Knowing.

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