Investing wisdom from: The Myth of the Rational Market: A History of Risk, Reward, and Delusion on Wall Street by Justin Fox. This book is a history of the developments in academia and on Wall St that lead to the belief that market prices are accurate predictors of asset prices (stocks, bonds, real estate, oil, gold etc.).
History has shown that the financial models that depended on this premise failed badly.

But,  most investors,  (those investing in their 401K plans) have very little chance of deviating away from the idea that stock and bond prices are efficient – that the average investor has little chance of predicting stock/bond prices.  At the end of the book Fox writes:

“First, its hard to beat the market. If you have money to invest, the only sensible place to start is with the assumption that the market is smarter than you. You don’t have to stop there. But if you do come up with an idea for beating the market, you need a model that explains why everybody else isn’t already doing the same thing you are. ….
If you’re picking somebody else to manage your money, the chances of finding a market-beating path are even harder. You’re now paying a fee that cuts into your performance. Since retiring as CEO of Vanguard, Jack Bogle has published a series of studies on the determinants of mutual fund performance. The only measure that seems to have any predictive value is the management fee funds charge. The higher the fee the worse the subsequent performance. Cost is thus a good, all-purpose, starting point in picking a money manager – one likely, but not certain to lead one toward index funds. There are surely some high-cost money managers who more than earn their fees. Maybe you can find one. But you can’t just do it on the basis of performance – you need to have some cogent explanation of why a particular manager can beat the market. Good Luck.”