Support & resistance

Support is an area where buying has repeatedly been strong enough to stop a fall; resistance is where selling has repeatedly stopped a rise. They work because of memory: traders who bought there defend it, traders who missed it wait for a retest, and trapped traders want out at break-even.

Levels are zones rather than exact prices, and the strongest ones were touched more than once, produced sharp reactions, and are visible on a higher timeframe. Broken resistance that price holds above frequently becomes support on the retest.