You will only lose in trading once you will sell a coin/token lesser than the price you bought it and for me it is normal to have a paper loss.
If this person is afraid of losing the money in trading, better for him to not to come here. This world is an amalgamation of profits and losses both. No one had a tenure of trading without any loss. Although bitcoins are so amazing and they dont let you down if you put some good effort in the field but still people sometimes lose little or more in trading for bitcoins. It happens.