Recovery maths after a loss

In German: Erholungsmathematik nach Verlusten

Losses and gains are not symmetrical: after a loss of L the gain needed to break even is L ÷ (1 − L). −10 % needs +11 %, −25 % needs +33 %, −50 % needs +100 % and −80 % needs +400 %. This is why limiting large losses matters more than catching every gain.