You can hide a token from your holdings list on the Home screen and on the Portfolio tab. On the mobile app, press and hold the token row and choose Hide token. On the web app, right-click the token row.
On the mobile app the row is dimmed and moves under Show hidden at the bottom of the list, the same control that shows small remaining balances. Hiding works on open positions only, not closed ones.
On the web app, Show hidden is its own checkbox in the Your positions header, next to Show dust, and it switches off again when you reload the page.
Bringing a token back
Tap Show hidden at the bottom of your holdings list (on the web app, tick Show hidden in the Your positions header).
Press and hold the dimmed token row (right-click on the web app).
Choose Unhide token.
Hiding is display only and is saved on the device you set it on. The token and its value stay in your wallet and in your balance, and nothing is sold or moved. Small remaining balances are hidden automatically and are explained in https://help.fomo.family/en/articles/15171789-what-happens-to-small-remaining-balances.