Robert D. Edwards and John Magee, in *Technical Analysis of Stock Trends* (first edition 1948, now in its eleventh edition more than seven decades later), wrote that 'support and resistance are the very foundation upon which the entire structure of technical analysis is built.' The two levels are not abstract — they are the visible record of where, historically, enough buyers gathered to absorb selling pressure (a floor) or enough sellers gathered to absorb buying pressure (a ceiling).

When the same price level is tested multiple times and holds, the level acquires institutional memory: market participants remember it, set orders against it, and in doing so reinforce its function until something material changes. Trend, in the Edwards-Magee framework, is simply the directional bias produced by support holding and resistance breaking (uptrend), or by resistance holding and support breaking (downtrend). This lesson teaches the architecture honestly: levels work because participants make them work, the work has limits, and the levels that hold most reliably are those marked by structural events visible in the volume record.