Pendle PT/YT Tracking: One Asset Split Into Two, With a Clock

What is unique about a Pendle position is that it splits one yield-bearing asset into two tradable claims, a Principal Token and a Yield Token, each governed by the same maturity date: PT redeems 1:1 for the underlying at maturity and trades at a discount before, while YT carries the future yield and decays to zero at maturity. Track them as two ordinary tokens and you mis-value a discounted PT, a decaying YT, and lose the link between them. This guide is the PT/YT model and its maturity dynamics, one spoke of the broader multi-wallet aggregation problem applied to yield tokenization.

How a Pendle PT/YT position behaves

• Pendle splits a yield-bearing asset into a Principal Token (PT) and a Yield Token (YT) with a shared maturity.
• PT redeems 1:1 for the underlying at maturity and, before maturity, trades at a discount that narrows toward the date.
• YT carries the future yield until maturity and then decays toward zero.
• Do not value PT at par before maturity; use the discounted market price plus the maturity clock.
• PT and YT are one decomposition of a single underlying, so keep the relationship rather than treating them as two unrelated tokens.
• Tax is jurisdiction-specific: track the mechanics, confirm tax separately. The decomposition discipline matches DeFi position reconciliation, and the NFT-LP fee-split parallel is Uniswap V3 LP tracking.

One asset, two tokens, one clock

Pendle is a yield-tokenization protocol. It splits a yield-bearing asset into:

• PT (Principal Token), the principal portion, redeemable 1:1 for the underlying at maturity and trading at a discount before then;
• YT (Yield Token), the right to the asset's future yield until maturity.

Both share a maturity date, and that date governs their values. A PT/YT holding is not "two tokens"; it is a time-bound decomposition of one economic source.

What counts as the underlying

The underlying asset in Pendle is a Standardised Yield (SY) token — a Pendle-defined wrapper that standardises yield-bearing token interfaces. Common examples include:

• SY-stETH wrapping Lido's stETH
• SY-aUSDC wrapping Aave's aUSDC
• SY-wstETH wrapping wstETH
• SY-GLP wrapping GMX's GLP

The SY wrapper means the underlying yield source is always one further layer of abstraction. A tracker must record both the SY token address and the underlying protocol asset to produce a meaningful portfolio description.

PT: discounted until maturity

The defining PT property is that it redeems 1:1 for the underlying only at maturity. Before maturity it trades at a discount that narrows as maturity approaches. The tracking error to avoid is marking PT at par early, which overstates the position. PT's value is the discounted market price until maturity and par thereafter, so a tracker must apply the time-to-maturity dynamics, not face value.

The implied yield and price convergence

PT price converges from its discounted level to par as the maturity date approaches. The implied yield is:

impliedAPY = (1 / PT_price)^(365 / daysToMaturity) - 1

A tracker that prices PT at par immediately after minting overstates the position by the full discount. Conversely, a tracker that continues to price PT at its market discount after maturity has passed (and redemption is available) understates the position. At maturity, PT = 1 underlying unit; the tracker must switch from market pricing to par.

YT: a decaying claim

YT carries the yield until maturity. As maturity nears, the remaining yield it represents shrinks, so YT trends toward zero at maturity and stops generating yield then. A portfolio view must model YT as a decaying, time-bound claim, not a stable token. Holding YT past maturity is holding something with no remaining yield rights, a state a naive tracker will still show as a balance.

YT and the underlying yield stream

While YT is held, the holder receives the underlying asset's yield continuously (e.g. stETH rebases, aUSDC interest). This yield stream must be tracked separately from the YT balance itself. The yield accrual rate reflects the underlying protocol's yield, and the tax characterisation of that yield (income vs capital) depends on the jurisdiction.

Keep PT and YT linked

Splitting into PT and YT, trading either, and redeeming or settling at maturity are linked events on the same underlying. Tracking must preserve the relationship and the maturity clock, not treat PT and YT as unrelated holdings, the same "decompose, keep the lineage" rule as DeFi position reconciliation.

Step-by-step: how to track a Pendle PT/YT position

1. Identify the market contract. Each Pendle market is deployed for a specific underlying SY token and maturity date. The market address encodes both. Pendle's subgraph and API expose active markets with their maturity timestamps.
2. Read PT and YT balances. Both are standard ERC-20 tokens with addresses specific to each market. Read balanceOf(user) for each. Note: holding PT without YT (or vice versa) is valid — they can be traded independently.
3. Record the maturity timestamp. Each market exposes expiry(). Convert to a calendar date. This is the clock that drives all valuation.
4. Value PT at market price, not par. Query the Pendle AMM or an oracle for the current PT/underlying exchange rate. Compute PT_value = PT_balance × PT_price × underlying_usd_price.
5. Value YT at market price and acknowledge decay. YT price is also quoted on the Pendle AMM. As maturity approaches, expect the price to fall toward zero. Compute YT_value = YT_balance × YT_price × underlying_usd_price.
6. Track the yield stream flowing to YT holders. Query the InterestData on the YT contract or monitor RedeemInterest events to capture the yield received by YT holders between snapshots.
7. At maturity: switch PT valuation to par. After expiry() is reached, PT redeems at 1:1. Set PT_value = PT_balance × underlying_usd_price. YT value drops to zero; remaining yield is settled in the final RedeemInterest call.
8. Classify events per jurisdiction — split, secondary trade, yield receipt, and redemption may each have different tax treatment.

Common errors and how to fix them

Error 1 — Valuing PT at par before maturity. The most common Pendle error. PT bought at a 15% discount is worth 85% of its face value today, not 100%. Marking it at par overstates the portfolio by the discount. Fix: always use the AMM market price or an oracle-derived discount for PT valuation; switch to par only after expiry().

Error 2 — Treating YT as a stable-value token. YT has economic value only because it entitles the holder to future yield. Past maturity it has no yield rights and is worth approximately zero. A tracker that retains the acquisition price as the market value of YT after maturity significantly overstates the position. Fix: model YT with a time-to-maturity decay; set value to zero after expiry().

Error 3 — Missing the yield stream from YT. While YT is held, the protocol routes the underlying yield to the YT holder. This yield accrues off-balance-sheet unless specifically tracked. A tracker that only monitors YT's ERC-20 balance misses the economic return on the YT position. Fix: monitor RedeemInterest events or query the YT contract's userInterest mapping to capture accrued yield.

Error 4 — Treating the PT/YT split as a disposal. Minting PT and YT from the underlying SY token may not be a taxable disposal — it is a decomposition of one asset into two claims on the same underlying. Hard-coding the split as a disposal manufactures phantom gains. Fix: flag the split for jurisdiction-specific confirmation, defaulting to non-disposal in the tracking layer.

Tax is jurisdiction-specific

Whether the split, secondary trading of PT or YT, yield received via YT, or redemption at maturity is a taxable event is framework- and jurisdiction-specific and must not be assumed (see cost-basis methods and yield farming tracking). The split, discount, decay and maturity mechanics are the tracking layer; the tax characterisation is separate and adviser-confirmed.

Practical guidance

1. Model PT and YT as one decomposition of an underlying, with a shared maturity.
2. Value PT at its discounted price until maturity, never par early.
3. Model YT as a decaying claim trending to zero at maturity.
4. Track the maturity clock, since values are time-dependent, not static.
5. Confirm tax treatment of split, trade, yield and redemption per jurisdiction.
6. Reconcile PT/YT and maturity events to Pendle with an audit trail.

Choosing a tool for Pendle positions

Koinly and Zerion both model yield-tokenization positions, but Pendle's time-bound split is exactly where a generic balance reader fails. Before you rely on a Pendle figure, confirm the tool:

• prices PT from the AMM or an oracle-derived discount and only switches to par after the market's expiry(), rather than marking PT at face value on day one;
• models YT decay, setting its value toward zero as maturity nears and to zero after expiry, instead of holding the acquisition price;
• captures the yield stream routed to YT holders (via RedeemInterest or the contract's interest mapping), which sits off the YT balance;
• records the underlying SY wrapper and its source asset, and keeps PT and YT linked to one decomposition rather than two unrelated holdings.

Valuing PT at par early, or unlinking PT and YT, is the recurring Pendle error.

How Wag3s handles it

Wag3s Folio models a Pendle position as a linked PT/YT decomposition of one underlying, values PT at its discounted market price until maturity, models YT decay to zero, tracks the maturity clock and settlement, and surfaces the result for the jurisdiction-specific tax characterisation. See the Folio product page.

Further reading

• Uniswap V3 LP Position Tracking
• DeFi Position Reconciliation
• Yield Farming Tracking
• Liquid Restaking Token Accounting (LRTs)
• Crypto Cost Basis Methods 2026
• DeFi Lending Position Tracking

Sources

• Pendle — Principal Token (PT): PT represents the principal portion, redeems 1:1 for the accounting asset at maturity, and trades at a discount before then (its appreciation is the fixed yield).
• Pendle — Yield Token (YT): YT streams the underlying yield to the holder until maturity, after which it stops accruing.