technical analysis is a useful tool for traders, but we have to consider it's limitations. Technical analysis is basically based on assumption about the past market statistics and data, without putting into consideration other external factors . So traders should not 100 percent rely on technical analysis, they should use it together with other methods of analysis.
Some of its limitations includes
1.it is based on assumptions about past market trends, gotten from the past market price and volume data
2.it is a backward tool subject to interpretation from different traders.
3.Technical analysis will not provide the full details of the market, that is putting economic and global events into consideration,
so traders should put all these factors into consideration before making an investment decisions using technical analysis.
First of all, external market data can be used for technical analysis. People are constantly using them as data points and consider if some rumors for example have already priced in. Or if they will cause a perfect storm and trigger bots and traders to complete some patterns in the chart. And obviously sell the news is something people are waiting of if they know the date when rumor might get official press release.
And no trader trusts TA 100 percent certainty pecause accuracy of any TA, no matter what indicators they use is FAR from 100%. Percentage accuracies of it are really hard to measure because different time frames, different markets, different indicators can work very differently. It's far from exact science and i totally get why some people don't trust TA at all.
But imho we can't really judge TA as whole field of it consists of a huge spectrum of different techniques. Different traders don't trust different indicators or patterns. And some of them are laughing at meme lines, while they swear by elliot wave. And some are laughing trend lines calling them meme lines, and are perfectly fine using ichimoku cloud or combinantion of indicators and patters themselves, even if they would have so many settings and variables to look for that it would be impossible to measure any kind of accuracy for it.
And basically anyone can create an indicator. So if my indicator of solar eclipse cycles vs wick lenghts or something like it doesn't work, does that mean TA in general isn't accurate?
Personally i don't even care. I gave up complex indicators long ago as i can't calculate any probability for them. And i am using combination of "feeling" of the markets that comes with experience and combining them with most common patterns that i know people will be reacting to. And mostly looking at the big picture of the chart.