Small-Cap "Is it time to sell stocks?"

Some time ago i registered at The Motley Fool (rather strange name for trader's site)and since then they send me the promotional message "small cap growth". as i understand, their idea is to pick up the companies with small capitalization and big potential for growth. actually never read such kind of emails, call them spam and delete. this evening is different. looking for ideas what to buy, so decided to read. title - "Is It Time to Sell?". much writing about hidden gems, do not know what is this, never mind. there were a few goods things. the main thing - not to sell. never. the author says: "Consider this approach instead: Sell your stocks when you want to buy a house or furniture. Sell when you have too much in stocks and you want to buy some bonds, gold, or collectibles. Sell if you have too much in any one stock. But sell a stock, or the market, on valuation at you own peril.". interesting. there were a few examples that most of the stocks increased a few, even ten times in five years.... have time only untill christmas, but maybe should consider looking at cap numbers...