Trendlines are among the most fundamental tools in technical analysis, used to map out support and resistance areas on a price chart. There are two primary types: horizontal and diagonal trendlines. By connecting past price equilibrium points, traders can spot potential entry and exit zones.
Horizontal Trendlines: Battle Zones of Past Equilibrium
Horizontal trendlines connect price levels where the asset previously traded in a tight range — often areas of high volume and long duration. These levels act as strong support or resistance when revisited. For instance, Avalanche (AVAX) traded around $10 between August and October 2020; each subsequent pullback to that horizontal line triggered a sharp rally. Similarly, CAKE's $10 platform from early 2021 held as support multiple times until a decisive breakdown in 2022. Once a long-standing support is lost, it often flips into resistance — CAKE bounced off $10 in April 2022 but failed to break through (red circles).
Diagonal Trendlines: Dynamic Boundaries in Trends
Diagonal trendlines serve as dynamic support in uptrends and dynamic resistance in downtrends. The SAND/USD pair touched the same diagonal support line five times between January and April 2021, rallying 2,500% overall. Ren Protocol (REN) shows how the same diagonal line switched from support (March-September 2020) to resistance in 2021 as the trend reversed. Aave (AAVE) repeatedly rejected at a diagonal resistance before a major correction. Alpha token surged from the $0.25 horizontal support only to top out at a long-standing diagonal resistance from May 2021.
Channels: Entry/Exit Points and Fakeouts
When both diagonal support and resistance are drawn, price moves within a channel. The FET/BTC 8-hour chart illustrates a typical range where traders can buy at support and sell at resistance. However, breakouts from channels are often volatile, and rising channels statistically break downward more often. The ETH/BTC rising channel that lasted over a year eventually broke to the downside. Bitcoin itself exhibited a descending channel turning into a bull flag and a rising channel turning into a bear flag. Key tip: draw trendlines from candle bodies, not wicks — price may wick through a level, but closing bodies and subsequent candles provide more reliable confirmation.
Bitcoin Correlation: The Overlooked Variable
Nearly all altcoin prices correlate heavily with Bitcoin. Whether an altcoin precisely hits a trendline support or resistance often depends on where Bitcoin tops or bottoms that day. Zilliqa (ZIL) did not exactly touch its $0.03 horizontal support before exploding to $0.25 resistance because it had already hit a major support on the ZIL/BTC pair, coinciding with Bitcoin's local bottom at $34,000. Master Bitcoin's moves first to consistently profit in altcoin trades. Combining trendlines on multiple timeframes with body-based drawing and waiting for candle confirmation helps avoid bull and bear traps.