Drivers of stock values can be summed up in four positive terms - valuation, momentum, quality and profitability - and four negative: growth in assets, turnover, company size and share price volatility, Herman VanGenderen explains.

Investing for Fun and Profit: Valuation, momentum and profitability historically drive returns
Investing for Fun & Profit: It's both an art and a science -- but mostly science
Lack of movement on legalization drops valuations