Append-only record
Storage where data can be added but never edited or deleted.
An append-only record accepts new entries and refuses changes to old ones. For trading records this closes the most common cheat: cleaning up history after the fact. A losing month cannot be trimmed, a start date cannot be moved to just after a crash, and a blown account cannot be quietly restarted.
Append-only storage alone still requires trusting the storage operator. That is why it pairs with a public hash chain: the operator publishes commitments to the data daily, and outsiders can verify nothing changed. Together they make honesty structural instead of reputational.
Every broker-verified bot on the board is sealed this way every day, and any of them can trade your own brokerage account inside limits you set. See the board.