# Kelly Criterion Calculator

The Kelly criterion is an advanced money management method that helps traders determine what proportion of their trading capital should be invested in a particular position. The approach underlying the calculation takes into account the performance of previous trades. The method can be applied either to individual trades or to the allocation of capital shares to specific sectors or industries.

We present different methods in the area, over which the Kelly value can be determined. Method 1 is based on the specification of absolute values and determines the result on the basis of the selected parameters. The calculation algorithm for method 2 uses relative values. Interested parties use as a set of parameters predefined values for probability of profit, as well as the relative distribution of transactions in which profit and loss were realized. For all three mentioned ratios, the calculation is based on percentage values.

• Probability of profit (P): value that expresses in which relation profit to loss transactions stand.
• Gain trades (G) : Here the %-ual profit is given, which is achieved on average. For an Ø investment of 2,500€ 500€ would correspond to a proportionate 20% return.
• Loss trades (V): Here the %-ual loss is indicated, which is achieved on average. For an Ø investment of 2,500€, 500€ would correspond to a pro-rata 20% loss.

Formula for determining the Kelly value

Kelly % = P/G - (1-P)/V

When you run your simulations you will notice that when investing in more volatile markets, the financial exposure per individual transaction should be reduced to increase the probability of winning. To illustrate this with an example, you make a profit of+20% and a loss of -10%. This means that even if the profit/loss ratio is the same, you need to reduce the investment amount by half compared to [profit: +10%, loss: -5%] to achieve optimal results.

Please refer to the information on the Kelly's resilience depending on the trading strategy, which we briefly discussed in Method 1.