Demotion
Loss budget: if your funded calls lose more than 5 buys' worth from your best point, you go back to validation. One buy is your current tier's buy size, and your best point starts over each time you pass. It is checked each time a funded call closes, on closed results only.
That is the only automatic demotion: a bad day on its own doesn't demote you, and neither do losses on calls still open. Operators can also demote a caller by hand.
What happens next
No new treasury buys, from that moment on. Your open treasury positions are sold at market straight away, and profit you already earned is still paid. The bot DMs you why. Your next /call starts a free re-validation, from zero. An admin who promoted you before you passed validation can instead demote you back into that validation, with your calls still counting and the time you had left.