I'll never know for sure, but it's a long run over eight years or so. I rarely buy shares in specific companies, and even more rarely sell, so I can see that they outpace the index funds I buy. I could be just lucky. I buy individual companies basically entirely based on reading the news, and if I'm reading it in the news, the professionals knew it long before I did.
I used to assume that if I read it in the news, it was all priced in and there was no point in me buying, but I noticed that often, it wasn't. Maybe I just got lucky and I miss the news reports on the companies that subsequently crash.
For example if you were closely following video game enthusiast press you may have found out a lot about Nintendo's mobile game plans much sooner than more typical investors which may only read newspapers such as the Financial Times and WSJ, which devote limited column inches to the activities of video game companies.
I used to assume that if I read it in the news, it was all priced in and there was no point in me buying, but I noticed that often, it wasn't. Maybe I just got lucky and I miss the news reports on the companies that subsequently crash.