When it comes to picking companies that can do great things for your portfolio, there are any number of criteria you can choose. Are they temporarily undervalued? Do they have a massive opportunity ahead? Are they Rule Breakers that are changing their industries, or the whole world?

Well, Motley Fool co-founder David Gardner takes many things into account when he weighs investments, but this week, he's picking a five-stock sampler of companies that are poised for gains because they are riding massive trends. (Special thanks to listener Paul Knaapen, who asked David to chose the five Rule Breakers with the strongest tailwinds.)

In this segment of the Rule Breaker Investing podcast, he talks about telemedicine pioneer Teladoc (NYSE:TDOC), and explains why he sees it going from unprofitable to unstoppable.

To catch full episodes of all The Motley Fool's free podcasts, check out our podcast center. To get started investing, check out our quick-start guide to investing in stocks. A full transcript follows the video.

This video was recorded on Sept. 4, 2019.

David Gardner: Stock No. 3, and it is Teladoc, ticker TDOC. Teladoc's stock as we speak is trading around $56 a share. It's a $4 billion market cap. By the way, market cap, yeah, the game show, coming later this month. I first picked Teladoc for Rule Breakers members on November 22nd, 2017. That sounds like it was right around Thanksgiving. Well, let's give thanks, because ever since then, Teladoc is up 70%; the market up 17%. So, from $34 to $56. It's been a wonderful, still under two-year run for this emergent company.

Now, what's the tailwind that you or I might have identified that seems to me sits behind and powers Teladoc and many other companies? Well, trick question because I think I see two tailwinds that I want to identify. The first is cheaper healthcare. There is so much attention being paid, especially in the U.S. today, on how to make healthcare cheaper. Anybody who can bring something that would make it cheaper and easier seems to me very well positioned. That's tailwind No. 1 that's going to benefit and is benefiting Teladoc. No. 2, of course, is video conferencing. If you think about a recent IPO like Zoom, a very successful though still emergent, early company. You might be Zooming yourself these days. I do it quite a lot. There are other companies out there, too. BlueJeans or just Skype. There are a lot of different apps that we're all using to video conference. We're all increasingly getting familiar and comfortable with -- well, when it just works, anyway -- video conferencing. So, when you put video conferencing together with cheaper healthcare, that sounds a little bit like telemedicine to me. So, I guess it's not a big surprise that Teladoc in its most recent quarter had grown at sales 38% higher over the year before. It's been growing strongly and steadily. By the way, a good sign that you've found a stock with a tailwind blow is that kind of sales growth. After all, tailwinds should lead to well above average sales growth. Now, not every company can turn sales growth into profits. You should always be suspect of companies that haven't done it. By the way, Teladoc is one of them. Teladoc is not making money, yet. At present, it is a money-losing operation. But it is the Rule Breaker. It is the company that got out first at scale with a brand that we recognize. For a lot of you, you might have Teladoc as one of your corporate benefits today. Increasingly, that's how people are finding telemedicine, through their corporate employer, who might make it a benefit for you. By the way, if you don't have that benefit at work, I would suggest that you go talk to your benefits person or the CEO of the company, or maybe that's you, and consider giving that as a benefit to your employees. It certainly would help our stock, TDOC. But I think it'll also help your employees. We don't always have the time to take Junior down to the doctor. Sometimes we don't even need to do that. We could get a quick, easy answer via video conferencing. By the way, you can do it over the desktop or the phone. Teladoc is working increasingly to make this as accessible as possible for as many people as possible. I should mention, by the way, that the stock took a hit in December when it was revealed that at the time, its chief operating officer was having an affair with a woman 24 years his junior, which may or may not have included some stock tips about when she should sell shares of the company. That didn't go down very well. I didn't like to hear that. I know the market didn't, either. That gentlemen resigned effective January 1st, 2019, so, starting the year off right for shareholders. Teladoc has been bouncing up and down a little bit since. But, of course, we're not about what already happened. We're about what's going to happen next. This looks like, to me, a stock with a tailwind blow.