[turingcompeteme]

I hope they aren't just using 13Fs to determine hedgefund holdings. I saw one being filed recently and I was amazed at how useless they are for determining a funds actual positions.

You don't need to report short positions. This resulted in many scenarios where we were short a company, but from our filings, it looked like we were long. 3 examples:

- Class A and B shares. If you are long one and short the other, only the long shows up.

- Own the stock, but sold calls? Don't need to report the calls. Plus, options that are reported are done so as if they are fully exercisable.

- Debt, Convertible debt, and types of warrants and other instruments are not reported.

So don't use them to determine a fund's thinking.

[exHFguy1]

Agree 100% with this. 13Fs are not indicative of most HFs actual bets. Especially if they are running strategies where a bet consists of a bundle of securities (Eg convert arbitrage).

Also, Given delay in reporting, you’d just be getting in after they get in and likely they get out before you do. So the aggregate impact costs from this strategy becomes their alpha. Hence why some of these LS guys always talk up their positions.

[AznHisoka]

Agree with the second. Making money in stocks is not just what to invest in, but when.

If you bought FB in the beginning of July just after a hedge fund reported it (but they actually bought in April and sold in July) that would have been bad for you.