The best investing advice I ever received was from Tom Gardner. I couldn't tell you when or where he said it, or what I was doing when I heard it, but I remember the words distinctly.

"Study the masters," he said.

It's an oft-repeated theme here at The Motley Fool. We think that great investors can be great teachers when they expose you to what they're buying, and why. That's why we follow Buffett so closely. It's also why we created Motley Fool CAPS, a 125,000-strong community of stock pickers where ideas flow freely.

My experience is that the best learning happens when you combine good tools. Here, in this column, we'll compare data from Morningstar and CAPS to track which top investors are buying the best stocks in CAPS -- the ones that are proven to outperform -- and why.

Today's guinea pig? Gaming guru Activision Blizzard (NASDAQ:ATVI). Each of these three high-rated funds have been buying shares, reports Morningstar:

Fund

Morningstar Rating

Shares Bought

Other Recent Buys

Waddell & Reed Advantage

(UNCMX)

*****

2,775,000

JPMorgan Chase (NYSE:JPM)

American Century Heritage

(TWHIX)

*****

2,010,000

Monsanto (NYSE:MON)

Fidelity Contrafund

(FCNTX)

*****

1,190,000

Wells Fargo (NYSE:WFC)

Source: Morningstar.com.

And here's a look at superstar CAPS investors who think that Activision Blizzard will outperform:

All-Star

Player Rating

Other Recent Buys

SavvyCaveman

99.78

Echelon (NASDAQ:ELON)

ikkyu2

99.72

Bristol-Myers Squibb (NYSE:BMY)

leohaas

99.72

Strayer Education (NASDAQ:STRA)

Source: CAPS, up-to-date as of Dec. 30.

They've good reason. The expansion version of World of Warcraft became the fastest-selling PC game of all time just weeks after its November release. All-Star ikkyu2 saw it coming. Almost. "How'd I miss this? Blizzard's WoW is the biggest cash cow in video game history. It's fundamentally redefined gaming for a new century," our Fool wrote in August.

It's a theme SavvyCaveman would echo on Christmas Eve: "Blizzard releases best selling games every time. Any company that would empower that kind of brilliance is an outperform."

Most CAPS members agree. Of the 3,114 investors who've rated this Stock Advisor selection, 3,035 -- or 97.5% -- say it will beat the market. What do you think about Activision Blizzard, or any of the more than 5,000 stocks we're tracking in Motley Fool CAPS? Let us know by logging in now; it's 100% free to participate.

On Jan. 12, 2009, Fool co-founder David Gardner, Jeff Fischer, and their Motley Fool Pro team will accept new subscribers to their real-money portfolio service. Motley Fool Pro is investing $1 million of the Fool’s own money in long and short positions in a range of securities, including common stocks, put and call options, and exchange-traded funds (ETFs). They also incorporate proprietary CAPS "community intelligence" data into their research. To learn more about Motley Fool Pro and to receive a private invitation to join, simply enter your email address in the box below.