A rising wedge is a common chart pattern in technical analysis. The rising wedge is formed by drawing two ascending trendlines, one representing high prices and one representing low prices for an asset. The slope of the trendline representing the highs is lower than the slope of the trendline representing the lows, indicating that low prices are increasing more rapidly than high prices are. The resulting shape forms a gradually narrowing wedge, giving this pattern its name.
Because the trendlines that describe the rising wedge are ascending, rising wedges are occasionally falsely thought of as continuation patterns for an overall upward trend. The seeming upward trend in asset prices invites bullish traders to begin investing in the asset, while bearish traders continue selling off their holdings and maintaining the strong upper line of resistance. (This is reflected in the smaller slope of the upper trendline in the pattern.) Since prices refuse to break the upper level of resistance, buying pressure gradually decreases, the lower level of support is broken, and the asset usually enters a strong downward trend. Thus a rising wedge should be taken as a strong sell signal and an indication that a market reversal is imminent.