What companies are tomorrow's big winners? In our ongoing series, I'm chatting with members of our team at Fool HQ to discover the stocks on their watchlists. (For your convenience, you can now create your own watchlist for free at Fool.com, giving you all the information you want on the companies you care most about in one spot; just go to www.MyWatchlist.com to get started).

Today, Motley Fool CFO Ollen Douglass shares one company that he owns and is thinking about discarding, one he owns that's just right, and one he's watching and is likely to buy.

Two he owns
Visa
(NYSE: V) recently got the kind of news that makes a value investor sit up and take notice. The payment network saw its shares drop more than 10% after the Federal Reserve issued a proposal that would dramatically limit the amount banks can charge in interchange fees on debit cards. Unfortunately, Ollen already owned shares of the company and, even worse, thinks this might just be the tip of the iceberg in terms of governmental protection intended to benefit consumers but harm those that make the transactions possible. While Visa doesn't issue the cards themselves and the new rules don't directly affect Visa and rival MasterCard (NYSE: MA), the pain for both might be indirect yet significant.

"When I bought shares, I was looking at debit-card purchases as the biggest growth drivers for the payment networks," he said. "But now, if banks can only charge up to $0.12 per transaction instead of the roughly $0.44 now, banks are going to be a lot less enthusiastic about issuing debit cards and encouraging their use, and Visa's share will be cut. It's always tough to get caught in the middle of a hot political debate, and that's where Visa is right now."

Ollen says he needs to decide whether this setback is overblown or temporary in nature, which could indicate an opportunity to add to his stake at a bargain, or whether it's just the beginning of a consumer-friendly regulatory spree that cuts into profits for banks and the networks that enable their transactions.

He's much happier with portfolio stalwart UPS (NYSE: UPS) -- and despite what you might think about CFOs, Ollen truly does possess the aptitude for true, unmitigated happiness. "That's one that I'm very happy to own right now," Ollen says. "It's an outstanding company and it's ready to capitalize on two growing consumer stories: first, people are starting to feel more comfortable with their economic situations so they're beginning to buy more consumer goods; and second, they're buying bigger items online, meaning UPS will be able to make more for shipping things like giant TVs. Together, these paint a very pretty picture for the company."

The only downside -- at least for someone who doesn't yet own the company -- is that the share price has been climbing strongly since mid-year and now trades near the top of its 52-week range. But keep the shipper in mind if you ever need a company to make your portfolio happy.

And one he's poised to buy
SanDisk
(Nasdaq: SNDK) isn't yet making Ollen's portfolio happy, but he's thinking about giving it a shot. The maker of flash memory cards -- the things that allow your digital camera and your smartphone to remember things even when the power is turned off -- is at the top of his watchlist. As the company moves deeper into the consumer arena, it's able to increase its margins, and that trend doesn't show any signs of abating, he says.

His one concern about the company is its seeming reliance on Toshiba, potentially a concentration risk in case the partnership falters. But a recent contract for a joint venture to build a factory together signals a healthy relationship, says Ollen. The company only recently came to his attention, so he still needs to perform his due diligence before committing. But he's optimistic that this company will be making the jump from watchlist to portfolio.

And that's why it pays to watch. You can make smarter investing decisions with your own version of My Watchlist, new and free from the Fool. Click below to start following one of the stocks mentioned above:

Roger Friedman doesn't own shares of any companies mentioned, but they're all now on his watchlist. The Fool owns shares of United Parcel Service, which is a Motley Fool Income Investor selection. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.