Quote from piezoe:
What Maler said is correct. With experience you will learn what news to discount (most of it) and what to pay attention too. For example Draghi's announcement wed pre-open, pay attention. Headlines claiming to explain why the market went up or down day to day, ignore. Analyst up- downgrades, pay attention because no matter how illogical, they will move price at least temporarily. Use your own judgement on whether the analyst makes sense. When they don't make sense, which is quite often, or they use words like "maybe" , "possibly", "could be" they are likely being used as pawns to manipulate a stock up or down. Down because the firm for whom the analyst works has shorted it, or because they want to accumulate it. Up because the firm has bought it, or because they want to dump it. Thus the big print, classic headline in Barron's telling everyone what a great buy GM is just weeks before they had to be rescued. That was so some major players could get out as the stock bounced. Use your common sense, if you were holding GM short, and you should have been, you'd either have to cover, knowing the bounce was coming, and get back in at a higher price, or have faith in your own judgement and hold through the bounce.
In general, Wall street brokers and analysts are either out and out criminals, or borderline criminals operating as close to the legal limits as they think they can get by with. Keep that in mind when the source of your "news" is Wall Street, or mainstream media, which gets their news ticker from Wall Street. When a CEO, e.g., Tesla, comes out and says shorts will be sorry, or things couldn't not be more wonderful, when common sense tells you a prudent person would have some concerns, it is time to take note. When a company is known to be on the ropes, and they are on their third CFO in 9 months, and the CEO gives a glowing report of how well things are going, sit up and take notice. All CEOs lie even when they don't have to. It is a major qualification for the job.