What is Sidereal?

Start with something familiar. Put money in a savings account and you own two things at once: the money you put in (the principal) and the stream of interest it earns (the yield). The interest rate floats. Some months it pays more, some months less, and you have no say in it. As long as the two are bundled together, you hold both, whether you want both or not.

Sidereal unbundles them. A deposit is split into two tokens:

• PT (Principal Token) is the deposit itself. Each PT pays back exactly one dollar of principal on a fixed date, called the maturity. Until that date it sells for slightly less than a dollar, so buying PT and simply waiting earns a fixed, known return. No guessing about where rates go.
• YT (Yield Token) is the interest stream. It collects all the variable interest the deposit earns between now and maturity, and you can collect it as you go. When maturity arrives the stream ends, and from then on YT is worth nothing.

Both tokens trade freely, which turns interest rates themselves into something you can take a position on. Think rates will fall? Buy PT and lock in today’s rate. Think rates will rise? Buy YT and collect the upside.

The one rule everything follows

Splitting starts from SY (Standardized Yield), which is simply your deposit in token form: a receipt that grows in value as interest accrues. The protocol keeps one value identity true:

PT + YT = SY

The equation is about value, not fixed token counts. If one SY share is worth R units of underlying, splitting it mints R PT and R YT face units. Before maturity, handing back equal PT and YT face amounts returns the corresponding SY shares at the current exchange rate. The split changes the packaging of the position, not its combined claim.

The first market

The live market is built on the Blend v2 USDC lending pool on Stellar mainnet. USDC you deposit is lent out through Blend, and the interest borrowers pay is the yield being split. The rate Sidereal reports is read straight from the Blend position itself; no person sets it. Each market has a fixed maturity date. After it, PT holders take their principal back one-for-one and the market winds down.

How the pieces fit

             You
              |  deposit USDC
              v
        SY wrapper          your deposit, as a token (earns Blend interest)
              |  split
              v
         Tokenizer          holds the SY, issues PT and YT
           /      \
          v        v
        PT          YT
        |            |
   get principal   collect interest
  back at maturity   as it accrues

  One shared market prices PT, SY and YT against each other.

Each piece has its own page:

• SY, PT and YT: the three tokens and what each one is worth.
• Market lifecycle: what happens from deposit to maturity, in order.
• SY wrapper, Tokenizer, AMM, and Settlement: how the machinery works under the hood.
• Guides: step-by-step walkthroughs of every action in the app.

Status