The year of 2015 was the very first full year I spent invested in securities. Rather than imitate the pros by starting to write publicly about my performance when I get good, I decided it would be more productive to begin right away.

Since these are personal figures, instead of revealing actual money figures I chose a more important measure of the worth of money to me (and I suppose to most non-rich people): months of life in current regular living conditions.

Expressed in months of living expenses, my total savings at the end of 2015 are at about 3 to 4.

Performance in securities was -41% for the year.

Overall savings variation was -2.2% for the year. The only redeeming in overall performance when compared to securities was brought by operating profits (as they call it: working, getting paid and not spending it all).

I adhere to my ever improving version of Ben Graham’s investment philosophy, with added knowledge from numerous other people, namely Buffett, Munger, Klarman, Marks and Parisotto. Therefore it may not be surprising to learn that total number of transactions this year was three. All of the three were purchases, going long 2 different companies. No leverage was employed.

It’s hard to look at a dip of 41% and not think you’ve made mistakes. So let’s get to them: the first one was buying into a company with high debt-to-equity (0.71 at the time), Petrobras. Prudence says don’t touch anything above 0.5, even though it’s easy to spot companies at 3 and greater. I actually built the position in Petrobras in late ’14. As an unprecedented sequence of bad things was uncovered in and around the company, and the Real lost a lot of value, Petrobras’ debt-to-equity more than doubled to 1.57. Talk about ignoring a margin of safety. The price of the stock didn’t fall quite as much this year, 11%.

All the other companies in the portfolio, which also dropped in value, belong to mining or steel. None seemed too burdened by debt, and I believed I had purchased them at a low enough valuation, but their usually long cycle still had a far deeper bottom awaiting them — and that’s assuming we touched bottom at all.

When there are so many companies costing one tenth to one fifth of what they did just two years earlier, as is the case now in Brazil, opportunities are likely to arise. While staying cognizant of the opportunity cost incurred, and my limitations in selecting and analyzing stocks (working on it), I continue to see things in at least a 3-to-5-year perspective, and remain quite optimistic about the current portfolio and possible new additions next year.

The financial crisis of 2007-09 was quite unforgettable. It became easy to see the connections between Wall Street and people’s livelihoods half a world apart.

Up until then, I had taken no interest in stocks or bonds. I had no money, and the investing industry seemed to me like a casino for people who cared for nothing more than piling up money, if all went well.

Well, things were going terribly, but in the middle of all that wreckage you’d hear about one man swimming against the tide while being hailed as some kind of savior. That man was Warren Buffett.

My curiosity was aroused, so I proceeded to read up on the guy. It didn’t happen overnight, but it’s fair to say he opened a vast new mental latticework for me.

Although there’s much I could write on his philosophy, this time I’ll stick with a slice of a rule of thumb we can find in the writings of Buffett’s teacher Ben Graham: when looking for companies unburdened by debt, favor the ones with a ratio between debt and net equity of less than 0.5.

It makes sense: if all a man has amassed his whole life is $100,000 but he owes $85,000 to the bank – a ratio of 0.85 –, it will likely be a long while before he’s paid his debt down and is able to comfortably grow his net worth.

So I took to looking at these numbers from several quasi-randomly chosen companies listed on the Brazilian Stock Exchange, over 10 years for each issue whenever possible.

There are many details regarding criteria for picking the right balance sheet lines to yield the total debt I don’t yet fully grasp. This spreadsheet is where I compile the numbers.