What is the difference between practical risk and theoretical risk?

What is the difference between practical risk and theoretical risk?

The below example will illustrate the difference between practical and theoretical risk.

Say you buy 10 stocks at $15.00. THEORETICALLY, the stock price can go to zero tomorrow and you can lose all the money you have invested in this stock, which is $150. Therefore, your THEORETICAL risk is $150.

However, with the way we trade, having a stock price collapsing to zero overnight is highly unlikely to happen and we always have a stop loss in place. Say your stop loss is at $14, i.e. you will sell the stocks at a loss of $1 per share if the stock price turns against you after your trade is triggered. If this happens, you will lose a total of $10 on the trade. This $10 risk is your PRACTICAL risk as, if you are in a losing trade, this is the more likely scenario than the stock price gapping to zero.


Theoretical Risk is sometimes referred to as Absolute Risk.