Paraphrasing Gary Simms’ second question from his earlier comment:

Our methodology provides that we realize gains when we sell our shares because the  companies in which we invest steadily increase their earnings while we hold their stock. Assuming we paid a reasonable multiple of earnings (PE) when we bought it, by later selling it at a similar multiple, the sale price will reflect that increase in earnings.

As an example: if we pay 20 times earnings for the shares of a company earning $1 per share, and, five years later, the company is earning $2 per share. Selling it at a PE of 20 would produce a sale price of $40. Thus we’ve doubled our investment. 

His question is simply, "What if the earnings growth is right on schedule, but the PE isn’t near what it was when we’re ready to sell?"

The answer is a corollary to the answer to the first question. The PE is the price divided by the earnings. Therefore, if the earnings have grown as expected, the PE is low only because the current market price is low. The herd was simply not paying a reasonable price for the shares because of some fantasy; i.e. a story, rumor, or other event or opinion that drives the market prices down. You should, therefore, be patient and wait for it to come back up. It will.

The very same rule applies here: "If the price of a stock has declined for any reason other than a decline in the fundamentals; i.e., growth of sales, profits, or earnings, then it will return to where it was. What goes down must come up and vice versa."

It’s probably a good time for a refresher. Read “What’s a PE and What’s It to Me?

s How to Invest, NAIC Veterans' Lounge, Successful Investing fundamental analysis, fundamentals, Patience, PE ratio, the herd