Obviously, consideration of costs is key, including opportunity costs. Of course capital isn't free. It's easy to figure out your cost of borrowing, but theorists went bonkers on the cost of equity capital. They say that if you're generating a 100% return on capital, then you shouldn't invest in something that generates an 80% return on capital. It's crazy.

Being short and seeing a promoter take the stock up is very irritating. It's not worth it to have that much irritation in your life.

I think the idea that the hedge fund manager gets lower taxes than the taxi driver or the physics professor is insane. The legislators who leave that policy in place are derelict in their duties to be rational and fair. There are plenty of them in both political parties. It's totally outrageous.

The big money is not in the buying and selling ... but in the waiting.

If you take sales presentations and brokers of commercial real estate and businesses... I'm 70 years old, I've never seen one I thought was even within hailing distance of objective truth.... 'incentive-caused bias,' causes this terrible abuse. And many of the people who are doing it you would be glad to have married into your family compared to what you're otherwise going to get.

It's dangerous to short stocks.

Someone will always be getting richer faster than you. This is not a tragedy.