Support / Resistance
Price levels that historically halt moves.
Support and resistance are price levels at which the price has historically paused, reversed, or consolidated. A support is a lower level where demand has repeatedly absorbed selling pressure: the price declined to that level and bounced. A resistance is an upper level where supply has repeatedly stopped buyers.
They are not predictions — they are statistical observations about where price has found equilibrium in the past. The theory is that such levels tend to concentrate orders (buyers waiting at support, sellers waiting at resistance) and therefore tend to repeat. When price breaks below a support, that level often becomes the new resistance, and vice versa: this is known as 'polarity inversion'.
Worked example
Apple (AAPL) between 2022 and 2024 touched the $170–$180 area four times and bounced each time: that level was a structural support. In summer 2023 it then broke through the $200 resistance on above-average volume — the breakout was validated. That $200 level subsequently became support in subsequent corrections.
The $310 resistance for Apple, tested multiple times in 2024, held for months. When it was broken to the upside on volume 2x the average, the market read it as a confirmed breakout. The $310 level then acted as support in the following weeks — the typical behavior of polarity inversion.
When it's used
Support and resistance serve two practical purposes. First, identifying price levels where the historical probability of a reaction is higher — useful for those who want to define potential entry zones or set stop-losses in a way that is reasoned against the technical structure. Second, evaluating the strength of a breakout: a resistance break on elevated volume is considered more reliable than one on thin volume.
Limits
Support and resistance levels are not guarantees. A support that has held four times may not hold a fifth — and often the break of a psychologically important support (e.g. a round number like $100 or $200) can accelerate selling. The identification of levels is also subjective: two technical analysts looking at the same chart will often identify different levels. Support/resistance is a descriptive framework, not a predictive system.
Frequently asked
How many times must a level be tested to be 'valid'?
Common convention: at least 2–3 touches over time, confirmed across multiple timeframes (daily and weekly). A level touched only once is anecdotal. Multiple touches confirmed on more than one timeframe are considered more robust. The longer the timeframe, the more significant the level.
What is a 'false breakout'?
A false breakout (or fakeout) occurs when price briefly exceeds a resistance level or breaks below a support, only to return to the other side within a few sessions. It is common when the breakout occurs on low volume. Experienced traders wait for a session close above resistance (not just an intraday touch) before considering the breakout valid.
Do support/resistance levels apply to ETFs and indices?
Yes. Indices (S&P 500, Nasdaq 100) have technical levels that are widely watched precisely because they are seen by millions of investors simultaneously — the concentration of expectations reinforces them. The same applies to liquid ETFs like SPY or QQQ.
Related terms
Educational definition. Not financial advice.