What's the best way to be in the position of emerging 500 Company?

Outside of being a company insider or being an industry expert....there is no way to find out. Even then, it is almost impossible to tell. If there was some way to know for sure, then it would not be called investing. Sounds like you are looking for an investing shortcut based on this and your previous question. There are thousands of people with stories like your teacher.....hell, I have one myself. I bought $100k of BAC when it was under $3 per share and sold at $4! While I would not be a millionaire if I held on.....I sure would be close! Stories like that are like an old fisherman's tale about how big the fish that got away was.