You'll see these terms throughout Fira. Here's what they mean for you.

The date your fixed-rate position settles. At maturity, everything resolves automatically — no action needed on your part.

If you hold a lending position to maturity, you receive the underlying asset back at face value. If you hold a borrowing position, your debt closes at the agreed cost.

You can exit before maturity by selling your position in the secondary market, but the price you receive depends on current market conditions — it's not guaranteed to reflect your original rate.

BT is what you hold when you lend at a fixed rate.

When you enter a fixed-rate lending position, you effectively acquire BT at a discount to $1. At maturity, that BT redeems 1:1 for the underlying asset — effectively worth ~$1. The gap between your purchase price and $1 is your fixed yield, locked in at entry.

Example: You acquire BT at $0.94. At maturity, it redeems at $1. That $0.06 difference is your fixed return.

Technical note: BT technically redeems for FW (the wrapped asset) rather than the base asset directly. FW may be worth slightly more than $1 at maturity due to accrued yield from rehypothecation. For simplicity, we approximate this as $1 throughout our documentation.

CT represents the interest component of a fixed-rate position.

Where BT captures the principal, CT captures the yield portion. CT holders benefit when interest rates are high or rising — its market value increases accordingly. CT is primarily of interest to yield traders who want direct exposure to rate movements.

As a standard lender or borrower on Fira, you generally won't need to interact with CT directly. The interface handles this in the background.

FW is the internal unit of account in Fira's fixed-rate markets.

When assets enter the Fira system, they get wrapped into FW. FW tokens accrue yield over time as the protocol puts idle liquidity to work. You encounter FW when providing liquidity to Fira's AMM pools.

Think of FW as the yield-bearing form of an underlying asset — similar in concept to how aTokens work in Aave, but within Fira's fixed-rate architecture.

You don't need to understand these tokens in detail to use Fira. The interface handles the complexity. When you lend, borrow, or add liquidity, the app manages BT, CT, and FW in the background. Understanding what they represent helps you make sense of where your yield comes from — but it's not required to get started.