I realize this is a pretty squishy question, but if you could assign some confidence level to a stock whose median analyst rating is "overweight," how confident do you feel in its prospects? Are there any historical probabilities showing how likely it is for a stock with positive ratings to go down in the near term (say, within 1-2 years)? I'm sure it has happened where companies viewed favorably tanked for whatever reason, but is that 1% of the time historically? 10% of the time? More?
For specifics, I've been holding stock in Oracle (Nasdaq:ORCL) for a long time, and it's done very well over the years. I feel good about the company, their business model, outlook for the future, etc. Its average analyst rating is "Overweight", so it doesn't feel like a particularly risky proposition. However, I have a fairly large amount of my total non-real estate investments in this ONE stock -- about 15% of total investments. The other 85% is well diversified in stocks, bonds, securities, etc. It feels risky to have so much piled into one company, but I'd also like to avoid pulling out of what has been (and appears to continue to be) a winning investment. I know no one can predict the future of what will happen with any one company, but do the analyst ratings have any historical backing for how reliable they are?