1) Technical analysis uses historical market data like prices and trading volumes to identify patterns that may forecast future price movements. It aims to determine optimal times to buy and sell securities.
2) Critics argue that technical analysis assumptions like past price patterns repeating are flawed given market efficiency, and trading rules may become self-fulfilling prophecies.
3) Various technical indicators are used to identify overbought or oversold markets, measure investor sentiment, and identify support/resistance levels and trends.