Hedge-fund managers that do the most research will post the best returns
Around 2008, I read some public filings by banks. I made only two back-of-the-napkin adjustments:
1) I combined off-balance sheet assets and liabilities into the balance sheet, and 
2) I changed the expected % losses to approximately that of Wells Fargo.<p>With those two simple adjustments, I saw that some big banks were in the hole by (combined) tens of billions of dollars.<p>The market prices for these banks made it clear that major investors either didn't read or didn't understand the data in the public filings.<p>Fun fact 1: My bank WaMu which was itself was maybe $0-$10B in the red so I immediately withdrew $2K in panic. I found that money hidden in my filing cabinet about 5 years ago.<p>Fun fact 2:  What was even more crazy is that a famous private equity firm (I think TPG) had just dumped in billions of dollars into WaMu but that still didn't fill the hole (and why would such a big firm be less sophisticated than a nobody like me?)<p>Fun fact 3: FDIC had ~$50B at the time, which maybe wouldn't cover the losses at the pessimistic end of my estimates.<p>Fun fact 4: In accounting classes, I identified 3 very shady areas of accounting: options, off-balance sheet entities, and pensions.  I believe the first two have since been fixed but I think pension accounting is still very shady so... beware.<p>Disclaimer: I studied finance and accounting in school and read 10-Ks in my spare time in the early 2000s so I have some knowledge of accounting shenanigans.  I also had some experience in real estate.  But that's about all the expertise it took.<p>(Several edits made to improve readability.)