Recently, I was reviewing how banks actually assess a company's financial health, and I came across something interesting: most people only talk about the liquidity ratio, but they miss a much more revealing indicator. I'm talking about the guarantee ratio, that number that tells you if a company has enough assets to cover all its debt, not just the upcoming year's.

The difference is crucial. While the liquidity ratio only looks at the immediate (what happens in the next 12 months), the guarantee ratio gives you the full picture. It's like comparing whether you have cash in your pocket today versus whether you have real assets to respond at any moment. Banks know this well: when you request a small loan with annual renewal, they'll ask for a good liquidity ratio. But if you want long-term financing for machinery or real estate, they'll definitely require a solid guarantee ratio.

Calculating it is surprisingly simple. You just need to divide total assets by total liabilities. That's all. If Tesla has $82.34 billion in assets and $36.44 billion in debt, its guarantee ratio is 2.259. Quite healthy. Boeing, on the other hand, once had $137.10 billion in assets but $152.95 billion in liabilities, giving it 0.896. That’s already concerning.

Now, here’s where most analysts go wrong. They see the number and move on. But that guarantee ratio only makes sense in context. Less than 1.5 indicates real risk of bankruptcy. Between 1.5 and 2.5 is normal. Above 2.5 could suggest that the company is underutilizing its debt capacity, although it’s not always bad. Tesla appears to be overloaded with assets, but that’s due to its business model: it needs massive investment in research. A tech company without assets is a dead tech company.

Revlon’s case is the perfect example of why you should watch this number. In September 2022, it had $5.020 billion in liabilities but only $2.52 billion in assets. Guarantee ratio of 0.5019. That wasn’t just a warning; it was a cry for help. And indeed, it went bankrupt shortly after.

The advantage of the guarantee ratio is that it works equally well for small companies and giants, is easy to obtain from any balance sheet, and has an impressive track record: all companies that went bankrupt previously showed this ratio as compromised. If you combine it with the liquidity ratio and some industry knowledge, you have a pretty powerful tool to identify problems before they explode.

What I learned is that you should never rely on a single number. Always look at the trend of the guarantee ratio over years, compare it with industry competitors, understand what the company does. But if that ratio consistently falls or stays below 1.5, then you have a legitimate red flag.