US Funds: Overconfident, Overconcentrated, and Overcrowded

What does it mean for a stock to be overcrowded? It's a new term to me. I looked for a definition in the article, and couldn't find an explicit one.

Does it mean a stock has a lot of investors with relatively small positions?

Googling only turned up 'crowded short'.

http://www.investopedia.com/terms/c/crowded-short.asp

Is that the same thing?

I've been investing in stocks for a while and this is a new term to me.