V I S O R

Strategies · beginner · 6 min

Support and Resistance

Support and resistance are the two most-used words in technical analysis. The idea is simple: prices seem to pause, and sometimes reverse, at certain levels — a floor where falls tend to slow (support) and a ceiling where rises tend to stall (resistance). This lesson is about what that really is, and how to read it without fooling yourself.

Why levels form

A level isn't magic in the price; it's a memory in the participants. A price where a lot of buying happened before is a price where buyers may step in again, and where people who sold too early may buy back. A price where a lot of selling happened is one where sellers may reappear. Round numbers, previous swing highs and lows (see Market Structure Basics), and prior consolidation areas all tend to act this way — not because the chart commands it, but because a lot of people are looking at the same reference points.

A well-known wrinkle: when a resistance level finally breaks, it often starts acting as support (and vice versa). The ceiling becomes the floor. Again, this is a statement about how participants behave around a remembered price, not a rule the market is obliged to obey.

Zones, not lines

The single most useful correction to make early: support and resistance are zones, not lines. Price rarely turns at one exact number. It turns somewhere in a band. Drawing a razor-thin line and expecting a reaction to the tick is how people convince themselves a level "failed" when it did roughly what it always does — react messily within a range. Think in areas.

Reading it honestly

Two cautions worth holding on to:

  1. Levels are obvious in hindsight and slippery in advance. It is easy to draw lines through past turns; it is much harder to know which of today's levels will matter. Confirmation bias does a lot of work here — you notice the level that held and forget the three that didn't.
  2. A level is an observation, not an instruction. "This zone has acted as resistance twice" is a description of the chart. It is not a signal to do anything at that zone. What, if anything, a level means for a decision is yours to judge — Visor describes the market and never tells you to trade a level.

Where the gates come in

Because levels are so easy to see after the fact, they are a favourite ingredient in strategies that look wonderful on a chart and evaporate under testing. Any rule built on "buy support, sell resistance" has to answer the same question as everything else in this track: does it beat a randomly-timed version of itself, and does it survive out-of-sample? Read How to Read a Robustness Report for the method, and The Golden Cross for a worked example of a famous idea meeting that test.

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