How we draw support and resistance zones (and why they're bands, not lines)
5 min read · data: 437-stock universe · descriptive study, not advice
Open any textbook chart and you will see support drawn as a crisp horizontal line, price bouncing off it to the rupee. Open a real chart and you will see price punching a few rupees through “support”, reversing, and leaving everyone who used the line as a switch feeling cheated. The line was never real. The zone was.
Why bands, not lines
A support level is not a price — it is a region where past selling was absorbed. Different participants acted at slightly different prices, on different days, with different order sizes. Collapsing that behaviour to a single number is theatre: it looks precise and measures nothing. So every zone on our stock pages is a band with an upper and lower edge, typically about one percent wide, and the page tells you both edges.
How the zones are computed
The method is deliberately boring and fully automatic — the same code runs on all 437 stocks every evening, with no hand-drawn lines and no hindsight edits:
- Find swing pivots. We detect swing highs and lows on daily bars. The most recent pivot is always flagged provisional — it can still repaint, and nothing downstream is allowed to lean on it.
- Cluster nearby pivots. Pivots within a small price tolerance of each other are merged into one zone. A cluster needs at least two independent touches before it earns a place on the page.
- Label, don’t predict. Each zone carries its touch count and the date of its last test. We describe zones with words like strong or moderate based on observable touch history — never with a probability that price “will” hold.
What a touch count actually tells you
Intuition says more touches = stronger level. Our own validation work pushed back on that: a level tested many times is also a level being worn down — crowding and fatigue are part of the story. That is why the pages report the touch count as a fact instead of converting it into a strength score. You get the observable; the interpretation stays with you.
The limitation
Zones are computed from daily closes and wicks; they know nothing about tomorrow’s news, block deals, or expiry mechanics. A zone holding 8 times in the past creates no obligation on the 9th test. These pages exist to give you an honest, consistently-computed map — what you do at the edges of the map is a decision, and decisions are yours. Educational market context, not investment advice.