Don't listen to what these porn stars have to say about investing

CNBC went to the Adult Video News (AVN) Awards and asked some of the stars of the adult film industry how they would invest $10,000 right now.

While some of the investment ideas offered might be attractive, the rationales offered by some of the actors and actresses reflect one of the most common mistakes made in investing: the assumption that good companies make good stocks.

Let's examine a few of the quotes CNBC got.

Jesse: "Apple. [The company] is always inventing new technology [and] everyone's going to want it, so it will never go down."

Anikka Albrite: "I'm a huge fan of biotechnology, so anything that seems like it's good for the future and the health of other people."

Kelly Shibari: "Tesla, absolutely. It's a great company. It's green. They're coming out with a more consumer friendly price point for the car. I think that's a really, really good idea."

Tasha Reign: "If I had $10K to invest in a company…I think I would invest in Uber-because I use it for everything and all of the porn community is obsessed with it, and so is LA and NY. Or maybe my favorite restaurant Chipotle."

Each of these four porn stars are off to a good start in that they have a sense of how these businesses work. They're attracted to things like growth and innovation.

However, not one of these porn stars address valuation. In other words, they don't consider the possibility that all of these growth prospects are already priced into the stock.

One could argue that Starbucks makes great coffee, and they might be right. But it's going for $100 a cup, than it's probably a bad purchase.

You'd be ill-advised to make investment decisions based on what these porn stars said.

But, two good things came out of CNBC's feature.

Porn star Ron Jeremy had some pretty good insight into the real estate market:

"Real estate. I own a few condos and they all went up. See, there have been a lot of economic problems with real estate, but...you don't get off the roller coaster in the middle of the ride…I didn't. Everything has gone back again. I have a bunch of good condos. They make a lot of money. I think that, right now, is the best place to invest. Entertainment is the worst place to invest."

Jeremy exhibited a valuable trait that's lacking in most investors. He didn't sell at the low.

There are countless studies in the field of behavioral finance that repeatedly show that investors tend to by high during the manias and sell low during panic. This is a money-losing strategy.

Ultimately, investing is hard. And even if we do understand investing, it's hard to be as disciplined as Ron Jeremy.

For most people, the best idea may just be to defer to a professional.

"I would put it into my [simplified employee pension] where my financial advisor makes all the decisions," Jessica Drake told CNBC.

Check out the whole feature at CNBC.com.