Every wallet doubles as a filing cabinet with the front removed, because the balance, the history and the counterparties are all one lookup away for anyone who has the address.
$ZEC answered that at the base layer with a shielded pool, where a balance can be held without being written into the public ledger, and on $SOL the opposite is true by design.
So the fix on Solana has to come from the app, not the chain.
Umbra is a confidential wallet built on Arcium for exactly that, holding funds in a shielded form and letting them be sent and swapped from there.
The work that makes it possible runs across a cluster of nodes as fragments, where no node holds enough to read what it is handling, and the correct result still comes back.
Solana records the outcome the way it records anything else, so an explorer shows the activity and the app stays auditable.
Umbra is one of fifteen teams now listed on Arcium's ecosystem page.
A wallet was never meant to be a public document, and Arcium is the layer letting a Solana one stop being read like one.