Dust

Dust is any balance that isn't worth moving: two dollars of USDT in an address where a sweep costs one dollar, or a tiny bitcoin output that would cost more to spend than it holds.

Payment systems handle it with minimums:

• A sweep minimum, so small balances wait until they're worth collecting.
• A minimum withdrawal, so customers can't request payouts that cost more in fees than they send.

Dust is also used in attacks. Tiny amounts, or worthless tokens, are sent to many addresses, either to trace activity or to plant look-alike addresses in transaction histories. See address poisoning.

On Valtu

Sweep tasks take a minimum USD value, so you never spend a dollar in fees to move two. Coins can have a minimum withdrawal, shown on each coin page. Tokens from contracts Valtu doesn't recognise are ignored rather than credited.