# I.3. What is the interest in trading? The magic of compound interest. Why is 15% per annum so important?

So, everything seems to be cool. But how much can you earn on trading? Let’s calculate using the example of a classic example.

Imagine that you managed to find a bank that is ready to take your money for growth for 100 years at 15% per annum with accumulation, i.e. annual accruals are taken back into circulation. Next, we put 1 ruble on the account. And let’s calculate what will come out of this enterprise (see Table 4).

Table 4. Compound interest.

Oh, a miracle! Our 1 ruble turns over 100 years into a huge 1 million 174 thousand 313 rubles. 45 kopecks. But how is this possible? This is called compound interest. Now you understand that no bank in the world will give you such an agreement at 15% per annum. Although the banks themselves are looking for earnings of much more than 15% per annum. And imagine if you invested 1,000,000 rubles in such an enterprise! Your savings over 100 years would amount to a fabulous 1.174 trillion. rubles or 15.657 billion . \$ at the rate of \$ 1 = 75 rubles. A fabulous sum, isn’t it?