Simple Moving Average (SMA)

Measures: the average price over the last n bars — the smoothed consensus of where the market has been trading.

Formula:

SMA_n(t) = (1/n) × Σ  C_(t−i)     for i = 0 … n−1

Calculation: sum the last n closes, divide by n. Computed as a rolling window (add the newest close, drop the oldest) for O(1) per bar.

Parameters: n = 20 (short-term mean), 50 (intermediate trend), 200 (long-term regime, display only in v1).

How Thresher uses it:

• Trend family: price above/below SMA50; SMA20 vs SMA50 stacking; SMA50 slope (current value vs its value 10 bars ago).
• Structure family: price vs SMA20 as the "20-bar mean" reference.
• Bollinger Bands (I.9) are built on SMA20.

Limitations: the SMA lags by construction — roughly n/2 bars behind a turn. It says nothing about how price got there (a slow grind and a violent whipsaw can produce the same SMA). The engine never uses an SMA alone; it always pairs level (above/below) with slope and with ADX trend-quality.

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