- **Similar:** [Ccyc](../ccyc/Ccyc.md), [ACP](../acp/acp.md) | **Complementary:** RSI for momentum confirmation | **Trading note:** Center of Gravity oscillator by Ehlers; leads price turns with minimal lag.
CG identifies potential turning points using the physics concept of weighted center of mass applied to a price window. Developed by John Ehlers, the oscillator measures where the "weight" of prices is concentrated within a lookback period, producing a leading indicator that oscillates around zero with minimal lag compared to traditional moving average crossover systems.
John Ehlers introduced the Center of Gravity oscillator in *Cybernetic Analysis for Stocks and Futures* (2002). Drawing from classical mechanics, the indicator applies the concept that the center of mass of a distribution reveals its balance point. In the price context, the CG identifies where momentum is concentrated within a sliding window. Unlike momentum oscillators that differentiate price (and amplify noise), CG integrates position-weighted price, providing smoother turning point detection. The indicator's leading characteristic arises from the weighting scheme: as new prices shift the balance point, the CG responds before the window's simple average would.
The term $\frac{n + 1}{2}$ is the geometric center of the window, centering the output around zero. When recent prices dominate, $CG > 0$ (bullish); when older prices dominate, $CG < 0$ (bearish).
The `RecalculateSums()` loop iterates over the full buffer each bar, making this O(N) per bar. For default $N = 10$: ~65 cycles. A periodic resync every 1000 bars maintains numerical stability.
