Every quarter, 45 days after the end of each quarter, big institutional money managers are required to disclose the stocks they bought or sold during the quarter. This is the so-called “smart money” laying out their cards.

While this is annoying to the money managers (it’s a little like playing poker with your cards face up for the rest of the table to see), it’s great for the rest of us. We can peek over the shoulders of some of the greatest investors in history to see what the smart money is buying.

Just don’t follow these picks blindly.

The 13-F reports provided to the SEC are a snapshot in time. There is no guarantee that the manager still owns the stock by the time we read the report. We also have no information about short positions or futures positions. So in reading the raw reports, we have no way of knowing if a manager is trulybullish on a particular stock … or if that stock is simply a piece of larger hedge or pair trade.

But if you’re familiar with the trading styles of the managers you follow (and I am), you can get a pretty good idea of what their intentions are.

So with no more ado, here are high-profile stocks the masters of the universe are buying… or selling.

Apple Inc.

I’ll start with iPhone maker Apple Inc. (NASDAQ:AAPL), which has become something of a punching bag for hedge fund titans. As Apple has struggled to grow in recent years, several big money investors have lost patience and moved on. Greenlight Capital’s David Einhorn sold 1.3 million shares last quarter, reducing his total by nearly 17%. Apple remains his largest single holding, however, at 12% of his portfolio.

Steve Cohen, Leon Cooperman and Jim Chanos also reduced their positions in Apple.

But interestingly, one very high-profile investor – Mr. Warren Buffett himself – made a large Apple purchase. Buffett raised his stake in Apple by more than 50%. Apple still remains a small position for Berkshire Hathaway at about 1% of the portfolio. But Buffett clearly likes what he sees, and his stake is growing.

I, for one, agree with Buffett here. Apple’s slow growth is mostly a result of impossible-to-top comps due to the unprecedented success of the iPhone 6. But as Apple’s sales cycle gets back to normal, you should see very steady growth in the years ahead. And as I wrote recently, yes, Apple’s cash hoard really is a sight to behold.

Recommended article: Piper Jaffray Pounds the Table on Apple 

General Motors Company

Speaking of David Einhorn, Greenlight Capital also poured a lot more money into General Motors Company (NYSE:GM). Einhorn picked up an additional 1.9 million shares, which boosts his total by about 13%. General Motors is his second-largest holding after Apple and makes up about 9% of his long portfolio.

Interestingly, Einhorn is mostly alone in this trade.

David Tepper has been unloading his formerly large position for the past year, and there aren’t too many large managers that have meaningful positions in the stock. But it is worth noting that Mohnish Pabrai — a well-respected value manager known for making concentrated bets — has 21% of his portfolio invested in GM warrants.

My bet is that Einhorn and Pabrai are rewarded for their independence here. General Motors is a steal at under $32 per share. At that price, the stock trades for an almost insulting 5 times earnings.

Yes, GM’s earnings are highly cyclical, so you have to take the price-to-earnings ratio with a grain of salt. But I expect demand to be above average for several years to come, as sales were exceptionally low for years after the 2008 meltdown and have only recently started to recover.

Facebook Inc

No CEO ever wants to get a letter from Third Point’s Daniel Loeb. Loeb is known for writing scathing letters to management teams that he sees as being in need of improvement … and then publicly posting the letters in an act of shaming.

Loeb is the quintessential activist investor. He likes to shake up companies to unlock value. So once you’re in his crosshairs, look out. You might not have that sweet C-suite gig much longer.

Interestingly, Loeb’s biggest recent addition — social media leader Facebook Inc (NASDAQ:FB) — is about as close to immune from shareholder activism as you can get. Founder Mark Zuckerberg holds a majority interest in the company via his Class B super-voting shares, and his control of the company is so complete, he reserves the right to appoint his own successor upon his death.

Facebook makes up about 4% of Loeb’s long portfolio, making it his fourth-largest pick. Given that he realistically has no ability to shape Facebook as an activist, we’re left to conclude that he simply likes the stock and considers it a good value.

Also read this: J.P. Morgan Highlights Five Main Investor Concerns for Facebook