He trades individual stocks. Maybe those stocks weakened despite the strength in the overall market...not sure.
Tech analysis should be anathema to me, but speaking anecdotally, I would say they do. Although: Better in some markets than others. They do until they don't People tend to see what they want to see, so they become irrelevant. A tendency towards self-fulfilling prophecy. Sometimes you see patterns in pure randomness. Feel free to test it yourself with a graph from a random number generator. Sometimes it tells you wonderful things about where large sellers and buyers are - Many times I've worked in and out of positions that created support and resistance points.
The first two posts of this thread seem to declare the thread a joke. Gloria says: Just draw some straight lines on chart and you will win money. Does that make any sense? Can you prove it works or it is a tale? MK says: I say no, especially in the modern algo-dominated markets. The burden of proof is on the trend-line believers, though. They need to either ... Why a joke? Because those who profit from lines (or channels) don't use them in a way that's naive enough for these posters. Or, too be honest, who would want to teach such twits something that was useful. Hmmm. Just more frustrated trolls?
In my opinon, trendline is the most efficient tool for technical analysis. Trendlines are very flexible since they work at any market, instrument or timeframe. In fact, most of price patterns e.g. triangles are based on trenlines.Actually, the concept of trendlines is very close to the concept of support and resistance levels. It is possible to say that trendlines are some sort of diagonal support and resistance lines. You can find trendlines on any charts and they will work almost the same way. At the same time, there are two main difficulties related to the use of trendlines for making trading decisions. First one is volatility. If it is either too high or, on the contrary, too low, trenlines would provide false signals or at least it would be difficult to interpret them. Second one is confirmation. When the price breaches the trendline we should make a decision either to open (or close) the position or just to draw a new, adjusted trendline. Some of the traders use various moving averages to get an additional confirmation. For example, if both prcie and 9 EMA cross the trendline it is more likely to be broken. Equity traders could also use VWAP. Another criteria that could be also useful is a consolidation after the breaching - if the price stays on the other side of the trendline for a few periods (depending on timeframe), this could constitute a trendline breaching. By the way, the way you draw trendlines is very important too. Thre numerous approach inclusing the use of close price or shadows, or bars confirmed by volume, or even drawing them inside the price range. That is why each trader will have to find the way that works best for his particular purposes.