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As someone who writes about stocks for a living, it should come as no surprise that I own several in my personal portfolio. In fact, the reason I write about investing stems from my passion for investing. However, what is interesting about my personal portfolio is that none of my top holdings lies within my area of expertise, which is the energy sector. Instead, my three biggest holdings are the direct result of my reliance on the expertise of others to help me uncover profitable investment ideas that I likely would not have considered on my own.

1. Lululemon Athletica -- 2% of my portfolio

Admittedly, I do not know a thing about yoga pants. Because of that, I probably would have never invested in the athletic apparel retailer if Motley Fool Rule Breakers had not recommended it. That said, my personal journey with Lululemon Athletica (NASDAQ:LULU) started in 2011, when I made a relatively small investment in the company because I saw promise in its growing popularity as a lifestyle brand as consumers became more conscious about their health. That said, it did not become a top holding of mine until 2014, when I added a big slug of shares as a result of several options trades recommended by sister service Motley Fool Options, which uses options to generate income on a company with a strong underlying business.

Speaking of its strong underlying business, last year Lululemon topped $2 billion in revenue for the first time in its history, and revenue has more than doubled since I bought my initial stake. That strong revenue growth continued in the first quarter, with it jumping 17% year over year while gross profit jumped 16%. Those results exceeded its expectations, leading the company to boost its full-year outlook. 

At the moment, I have covered calls written on the bulk of my Lululemon position, which, given the current stock price, could result in those shares being called away later this fall. That is fine by me. I will walk away with a tidy profit on the string of trades and reinvest the proceeds in new options trades on another fundamentally strong businesses. Meanwhile, I plan to hold my initial position in the stock for as long as it remains an active Rule Breakers recommendation.

2. Facebook -- 1.97% of my portfolio

Like most people my age, I set up a Facebook (NASDAQ:FB) profile pretty early in its existence to keep up to date with my college friends. That said, I never thought about investing the company because I did not understand how it made money. However, I am so glad I took the time to read through the advice of Motley Fool Pro, which led me to buy options on the company to invest in it shortly after its post-IPO plunge. At the time, Pro likened Facebook to Alphabet's (NASDAQ: GOOG)(NASDAQ: GOOGL) Google in its earlier days due to its ability to monetize its sharply growing user base.

Unlike many internet companies, especially in social media, Facebook outperformed the hype. In the first quarter, for example, advertising revenue surged 57%, resulting in earnings per share skyrocketing 189%. Meanwhile, daily active users continue to grow and were up 16% year over year.

Financial results like that drove immense gains in the stock price over the past few years, turning Facebook from a small initial investment into one of my largest holdings. In fact, if it were not for cashing out three-quarters of my position a few years ago to fund a portion of the down payment on my house, Facebook would be my largest holding by a wide margin. I cannot complain, however, because I held on to enough of the shares I converted from my original option position to matter. My hope is that one day these shares will fund a decent portion of my next home, which ideally will be at the beach.

3. Visa -- 1.93% of my portfolio

I stopped using cash years ago, instead opting to pay for virtually everything with credit cards. That switch not only made it easier to track expenses, but I got paid anywhere between 1% to 5% in cash back just for using my card. But I did not even think to consider buying Visa (NYSE:V) until Motley Fool Pro made the compelling case to buy shares last year.  

I initially overlooked Visa because I thought the company carried risky consumer loans. Instead, I learned that it licenses its brand and operates the largest electronic payment system in the world. Because of that, the company collects a growing stream of recurring revenue as more consumers stop using cash to make purchases. That was certainly the case in the first quarter, for example, when payments volume was up 12%. As a result of its stable business, Visa expects to generate about $7 billion in adjusted free cash flow this year, the bulk of which it will return to investors via a massive stock buyback.

I see Visa as a steady performer over the long term and wouldn't be surprised if it maintains its place as one of my top holding for years to come.

Investor takeaway

There's an adage on Wall Street to buy what you know. While that advice can uncover some great investments, it might cause investors to miss some great opportunities. That is certainly the case for me, with the bulk of my best-performing investments made well outside my area of expertise. That said, I did not blindly follow the advice of someone with a good track record, but instead was inspired to dig into ideas that I would have otherwise missed.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.