3 "Buy Now" Stocks from the World's Greatest Growth Portfolio

September 2012 has come and gone, and that means we are officially three-quarters of the way through the year. So far, including dividends reinvested, the S&P 500 has returned 14.6%. That's definitely above average, and nothing to be discouraged with.

And yet, if you had used my hypothetical "World's Greatest Growth Portfolio" as a guide, you would be up 24.3%. It's only been nine months, so I'm not declaring victory any time soon, but the results so far speak for themselves.

Below, I'll tell you what to keep your eye on in October, identify three stocks that I think are buys right now, and offer access to a special premium reports on five of the stocks in my portfolio.

Core

Source: Fool.com. All results accurate as of market open, October 1, 2012.

Tier One

Source: Fool.com. All results accurate as of market open, October 1, 2012.

Tier Two

Source: Fool.com. All results accurate as of market open, October 1, 2012.

Looking ahead to October, there are eight companies from this portfolio that are reporting earnings. They are listed below, along with analyst estimates, in chronological order.

Source: Thompson Reuters, E*TRADE.

Best buys right now
All three of my best buys for this month are also reporting earnings in the next few weeks. The first is Intuitive Surgical, a company that I recently vowed to purchase for my Roth IRA.

My thesis for Intuitive is simple: Though the majority of procedures are concentrated in hysterectomies and prostatectomies, I believe that as doctors continue to experiment with the daVinci machine, they will find that it is useful in ever more procedures. In particular, doctors are currently experimenting with urology, lobectomies, and head and neck procedures. Combine that with the fact that over 58% of revenue is now recurring (not from new daVinci sales), and I think the company is a solid buy.

Next on my list is Westport Innovations. The company designs natural gas engines that can be used in cars, trucks, and other heavy machinery. There are two important risks to understand with Westport. The first is that if natural gas isn't adopted as the fuel of choice by large fleets, the engine designs will be useless. The second is that other competitors may start trying to manufacture their own natural gas engines.

I will grant that both of these are worthy of consideration. But the company's recent 30% drop in share price has more to do with concerns over slowing orders from industrial companies. I think that's a short-term concern for the investor with a long-term time horizon. I would suggest putting all your money into Westport, but at today's prices, I think it's a buy.

Finally, we have Baidu, China's leading search engine. Investors seem to have given the company the cold shoulder since a report came out stating that the company was losing ground to rival Qihoo 360. I think it's a little too early to see how this will play out. Unseating a rival like Baidu that has a huge head start would be a monstrous accomplishment for Qihoo. And we also have to consider that even if Baidu loses market share, the growth of the Chinese Internet market alone could make up the difference.

Prepare yourself, Fool!
As I've shown, earnings season is just around the corner. Recently, our top analysts have started creating special premium reports on some of the most loved stocks in the Foolish universe. These reports also include access to real-time updates, like those that you'll get following a company's earnings release. These updates let you know, in plain English, what the news means for you.

Currently, we have reports available for Apple, Amazon, Baidu, MAKO Surgical, and Whole Foods. The first three companies are reporting this month.

If you only have time for one report, I'd suggest the "buy/sell" report on Apple. Evan Niu is out with new research on the iPhone 5. It's a free bonus. Sign up today and you'll get the initial report plus the iPhone 5 bonus and a year's worth of free updates. Click here to get started now.