Upgrades and downgrades can be useful but they may not be the most current form of trading information.
The problem with upgrades or downgrades is that they rely on the events which already happened; in most cases, the information is already built into the price of the stock.
Very often, after a company reports bad results, analysts will downgrade that company — how smart they are!
Of course, we all wish that they would do it before the results had been reported. Still, if a majority of analysts downgrade the stock, it might be prudent to seriously consider selling it.
If most analysts have upgraded the stock, it might be much safer to buy it or hold it in your portfolio.
Should I Listen to Commentators on Financial News Programs?
Should I Trust the Opinions Expressed by Various Financial Analysts?