Each flow is valued in USD at Comet's oracle price at its block, the price its liquidation engine reads. On the collateral side the last line, Market move, is the change in those prices since each flow.

The debt side adds up to what the position owes in USDT: borrowed, plus the interest accrued, less what was repaid and what an absorb cleared. Each event states the USDT balance the chain held at its block (the account's principal at the market's borrow index) and the interest since the previous event (the previous principal at this block's index, less the previous balance), so the interest between two events is exact to the base unit. Comet has no borrow or repay call: a supply into a debt repays it and lends the rest, and a withdrawal past the balance borrows. Between events the debt grows at the rate the market charged until the next one; after the last, at its borrow rate now.