Every figure is in USDT, this vault's debt token: Fluid prices nothing in USD, and the vault's oracle prices tBTC in USDT. Each tBTC flow is converted at that price, so on the collateral side the last line, Market move and interest since the last event, is the change in the price since each flow with the interest the collateral earned since the last event.

Each event states both balances just before and after it, read from the vault at its block, so the interest between two events is exact to the base unit: the collateral's is Interest earned, the debt's Interest accrued. Between events each balance grows at the rate the vault paid or charged until the next one (its interest over the balance and the time); after the last, at the vault's rate now, and today's figure is the vault's live read.