> ## Content Index
> Fetch the complete content index at: https://convexitydesk.com/llms.txt
> Use this file to discover other available public pages before exploring further.

# The Mechanical Engine: Decoding Regime Math (Gear 0-5)
- URL: https://convexitydesk.com/the-mechanical-engine-decoding-regime-math-gear-0-5/
- Published: 2026-08-27T17:27:10.000Z
- Updated: 2026-08-27T17:30:15.000Z
- Author: Convexity Desk

At Convexity Desk, we do not guess market direction. We measure it.

The colorful numbered squares running beneath the Daily PnL Trajectory chart are not arbitrary decorations—they represent our **Alpha Engine**, a strictly mechanical, algorithmic scoring system that dictates exactly how aggressive or defensive our portfolio posture should be.

Here is a full breakdown of the math powering the Alpha Engine and how we determine our Regime Gears.

---

## 1\. The Core Inputs (The Trend Score)

The engine analyzes the two most important ETFs for institutional rotation:

- **SPY** (S&P 500: Capitalization-Weighted)
- **RSP** (S&P 500: Equal-Weighted)

By tracking both, we instantly identify whether a rally is broad (healthy) or dangerously narrow (held up by a few mega-caps).

For each ETF, the engine computes a **Trend Score** from `0` to `3` every single day. The score is calculated using the 20-day Simple Moving Average (SMA) and the 50-day SMA.

The algorithmic logic is as follows:

1. `+1 point` if the Current Price > 50 SMA (Long-Term Trend is UP).
2. `+1 point` if the Current Price > 20 SMA (Short-Term Trend is UP).
3. `+1 point` if the 20 SMA > 50 SMA (Momentum is expanding).

**Example:** If SPY is trading above its 20 and 50 SMA, and the 20 SMA has crossed above the 50 SMA, SPY receives a perfect Trend Score of `3`.

---

## 2\. Calculating the Regime Gear (0 to 5)

Once we have the Trend Scores for both SPY and RSP, we cross-reference them to determine the global **Regime Gear**.

- **Gear 5 (Aggressive Bull):** `SPY Score = 3` AND `RSP Score = 3`. The market is in a flawless, broad-based uptrend. Maximize risk budget and scale into high-beta breakouts.
- **Gear 4 (Standard Bull):** `SPY Score >= 2` AND `RSP Score >= 2` (excluding the 3/3 scenario). The trend is definitively up, but momentum might be consolidating. Maintain core longs.
- **Gear 3 (Choppy / Neutral):** `SPY Score = 2` AND `RSP Score = 2`. The market is stalling or digesting a move.
- **Gear 2 (Divergence / Warning):** `SPY Score >= 2` AND `RSP Score < 2`. The Cap-Weighted index is holding up, but the Equal-Weight index is breaking down. This is the classic "narrow market" warning sign. Reduce leverage.
- **Gear 1 (Bearish Breadth):** `SPY Score < 2` AND `RSP Score >= 2`. The mega-caps are dragging down the index, but the broader market is holding. Highly volatile environment.
- **Gear 0 (Bear Market / Cash):** `SPY Score < 2` AND `RSP Score < 2`. Both indexes have broken their moving averages. Cut physical equities. Shift to cash and Volatility Risk Premium (options) strategies.

---

## 3\. Why This Matters

Emotional trading destroys alpha. By strictly adhering to the Regime Gear, we systematically eliminate the need to "predict" market crashes. When the gear drops to 0, we are already in cash. When the gear shifts to 5, we are fully deployed.