Rolling Z-Score (Quant Lab)

What does this Z-Score measure?
• src (default = close) → the value of the series you selected
• len → the window you are measuring based on the average of the last few bars
• Z ≈ 0 → price close to the average
• Z > 2 → price 2 standard deviations above the average (extremely positive deviation)
• Z < -2 → 2 standard deviations below the average (extremely negative deviation)

In modern mean-reversion strategies:
• Z > +2 → short / take profit candidate
• Z < –2 → long / dip buy candidate