Good investors are obviously those people who knows on what they are investing in. They have researched the company or the project for months or even observed it for a year. It is very simple as that because if you have not have done any of those things and you were just attracted by all the hype then that you are a bad investor.
Lets not be specific about the time of doing analysis. Someone can do analysis for a few days and invest while others may take long. None of this has any importance of being a good or bad investor.
A great investor can make money in any market. Doesn't matter if its a bull or a bear.
Making money in the bear market is only possible if you are doing shorting. I consider that as a very risky option. I dont know but I dont feel a "good" investor tries to make money in the bear run at all but wait it out. Always making money is something that is not appropriate. Everyone should have a sort of "time-out" and the bull run is just that.
They also have extreme patience and don't get caught in FOMO.
Sounds ideal and thus less possible.