5 Stocks to Buy Now for Your Retirement Portfolio

Hold your breath, Fools. I'm doing something today that I've never done before: talking about not one or two great stocks to buy now ... but five.

Why am I doing that? It all started three years ago, when I publicly pledged to put $40,000 of my own money behind a total of 10 stocks for my retirement portfolio. Following my recommendations, that amount has grown to $61,560 -- an amount I'm certainly not disappointed with.

But measured against the broader market, this portfolio is -- for the first time since its inception -- floating dangerously close to falling behind the S&P 500.

Source: YCharts. Prices accurate as of mid-day April 10, 2014.

As recently as December, this portfolio was outperforming the broader market by 16 percentage points. One way to look at its current performance is with disappointment -- but that wouldn't be very productive.

Instead, I think it's altogether better to look at this as a great buying opportunity. So here are the five stocks I think are definitely worthy of your consideration, broken into two subgroups.

3 stocks to buy now with sustainable competitive advantages
Sustainable competitive advantages offer shareholders more safety than other riskier choices. So here are three options that have this type of safety.

Baidu is China's largest search engine. The company's 64% market share of search in China is a huge and sustainable competitive advantage that should only improve as Baidu moves to dominate the mobile industry.

Though its stock is up over 70% in the past year, there's still a lot of incentive to buy shares. The company is the dominant search engine in China, and China is one of the world's fastest-growing large economies. As it stands now, there are still 744 million Chinese citizens who aren't using the Internet. As that number shrinks, Baidu stands to benefit.

Amazon has built out a network of expensive fulfillment centers that would make it impossible for any company to profitable match its scale. CEO Jeff Bezos has shown that he's not afraid to enter new markets and undercut the competition on price. In the end, his main goal is to create the number one company in the world when it comes to customer service.

As it stands now, e-commerce is growing like gangbusters, but according to Forrester Research, it still accounts for only 8% of all retail purchases. Amazon's stock is 20% off its yearly highs, and with so much room for growth in e-commerce, I think this is a great long-term bet.

Source: National Oilwell Varco. 

National Oilwell Varco, or NOV, which will soon be splitting into two separate businesses, is so ubiquitous that many refer to it as "No Other Vendor." That alone should tell you just how sustainable this company's competitive advantages are. As long as the world is looking for energy underground, NOV will be a force to be reckoned with.

But for a while now, Wall Street hasn't been showing the company much love. Instead of complaining, though, we can take advantage of it. NOV's backlog is at a record $16.2 billion, and demand for both floating and land rigs is strong, especially abroad.

2 riskier stocks to buy now
The reason these companies earn a "riskier" designation is because their advantages aren't quite as sustainable or stable.

First, we have Apple. The company has yet to come out with a new product or product line that really "wows" us since Steve Jobs passed away.

That being said, the company is trading for dirt cheap right now. The iPhone 6 is likely around the corner, CEO Tim Cook keeps tell us that big things are on the horizon, and aggressive buybacks and a nice dividend are added bonuses. If you believe the days of innovation at Apple are still alive, now's a good time to buy.

Source: Intuitive Surgical.

Finally we have Intuitive Surgical, maker of the da Vinci surgical robotic system. The company has been hit hard lately, as some have begun to question the efficacy of using the da Vinci in hysterectomies -- a major operation for the company -- and hospitals have become wary of spending millions on new machines in the era of the Affordable Care Act.

But da Vinci's new Xi machine, with the improved maneuverability of four pivoting arms and 3-D high definition imaging could eventually become a game-changer. Right now, urology and gynecology are the heavy hitters for the company, but that could easily expand into thoracic and head/neck surgeries in the coming years.

It's a risky stock because the company's success depends on doctors' continued adoption of the machine. If it really does help outcomes and recovery, it could be a big win. While that's still a big "if," it's one I think is worth investigating.