'Returnless risk' is not how you prepare for a decent retirement.

If you are not making any mistakes, you are being excessively risk-averse. Investing involves risk, and that means you will occasionally be wrong. And although it is okay to be wrong, it is not okay to stay wrong.

You, your employer and your plan's investment managers fail to follow even the most basic rules of investing. You overtrade, chase performance, do not think long term. All of you - All Of You - have done a horrible job managing your retirement plans.

Any investment bought via credit always runs the risk of margin calls and, eventually, liquidation.

What you pay for an investment is the single biggest determinant for how successful that investment will be. When equity prices are high, your returns will be lower. When they are cheap, your returns will be higher.

How are the cabs in your city? In Manhattan, where I work, they are rather awful.