Dynamic Support & Resistance based on SMI Crossover

Explanation:

SMI Calculation: The script calculates the Stochastic Momentum Index (SMI) and its signal line using the specified input lengths.

Crossover Detection: It detects when the SMI crosses above (crossUp) or below (crossDown) its signal line.

Period Tracking: The script keeps track of up and down periods based on SMI crossovers. During an up period, it records the lowest low (support), and during a down period, it records the highest high (resistance).

Support and Resistance Levels: When a crossover occurs, it captures the highest or lowest value since the last crossover to define dynamic resistance and support levels.

Midline Calculation: The midline is calculated as the average of the current support and resistance levels.

Buy and Sell Signals: Buy signals are generated when the close price crosses above the midline, and sell signals are generated when it crosses below.

Plotting: The support, resistance, and midline are plotted on the upper chart. Buy and sell signals are indicated with arrows. Trendlines are added for visual clarity.

Note: This indicator should be used in conjunction with other analysis tools and is intended for educational purposes. Always perform thorough analysis before making trading decisions.

Like all technical indicators, this script is based on historical data and may not predict future market movements.

Always perform due diligence and consider multiple factors when making trading decisions.