Fixed-Income Analytics, Refined

Quiet, accurate
bond mathematics ·
in a browser tab.

Bond settlement, round-trip P&L attribution, portfolio analytics, and a live US Treasury yield curve. One shared math engine, accuracy to a hundredth of a basis point, and a price that respects the individual analyst.

0.0001%yield tolerance
<50msclient-side calc
$100per year
Specimen · settlement
US91282CJM14
UST 4.25% 02/15/2035
SettlementApr 25, 2026 · T+2
Day countACT/ACT
Face value1,000,000
Yield (input)4.2510%
Clean price99.9912
Accrued · 69 days8,047.06
Modified duration7.312
DV01$731.16
Total invoice$1,007,960.54
USD · per dirty price 100.7961
The Five Modules

One engine. Five workflows.

Every module runs on the same pure-JavaScript bond-math library. Price a bond in the Calculator, trade it in P&L, manage it in Portfolio, benchmark it against the Treasury curve, and convert across currencies on the FX desk · without the number ever drifting between screens.

The Curve · Module 04

The shape of money,
at a glance.

Eleven tenors, from one-month bills to thirty-year bonds. Today, a week ago, a year ago · overlaid and annotated. The inversion is marked where it happens; the spreads are computed below.

US Treasury Constant-Maturity Curve
Apr 23, 2026 · end-of-day · source EODHD
Today1 week1 year
5.405.004.604.203.801M3M6M1Y2Y3Y5Y7Y10Y20Y30YYIELD (%)5.324.154.52INVERSION · SHORT-END ABOVE 2Ytrough · the belly
2s10s Spread
−17 bp
10Y 4.25 − 2Y 4.42
3m10y Spread
−93 bp
inverted
Curve Slope
−80 bp
30Y − 3M
Shape
Inverted
recession signal
Also coveredBond ETFs charted the same way · TLT, IEF, SHY, LQD, HYG, AGG · each with price, yield, duration and expense ratio.
The Canonical Example

We do not round.
We reconcile.

A six-percent semi-annual bond, thirty-three-sixty day count, bought on 2 January 2025 at a 5% yield, sold one year later at a 4% yield, on $1,000,000 face. Every fixed-income tool in the world should produce the same three numbers. We produce these:

  • I.Carry P&L+$52,091
  • II.Market Move P&L+$37,399
  • III.Total Revenue+$89,490

The test suite runs twenty-plus reference trades on every deploy. If any number drifts, the build does not ship.

Method · §6.1

Attribution, in four lines.

Repriced Entry=invoice @ buy yield, sale date
Carry P&L=Repriced − Buy + Coupons
Market Move=Sale − Repriced
Total=Carry + Market Move

Algebraically identical to sale minus purchase plus coupons. Intellectually, an answer to the question the cash P&L never asks: why did I make the money?

"

For settlement math, round-trip attribution and curve context, I want a scalpel that opens in a browser tab · nothing to install, nothing to learn, answers in seconds.

Platform Capabilities

Every capability that matters
for settlement & analytics.

01

Settlement Math, Reproducible

Clean price, dirty price, accrued interest, yield to maturity, modified duration and DV01 · computed under the conventions each bond was issued with. Reproducible to the counterparty's ticket.

02

Round-Trip Attribution

Total return split into Carry and Market-Move using the repriced-entry method. A proper answer to why the trade made money.

03

Portfolio Analytics

Aggregate yield, weighted duration, portfolio DV01, and a maturity ladder. Positions stored locally; export as JSON or CSV.

04

US Treasury Curve, Live

Eleven tenors with historical overlays and spread summaries. Inversion flagged automatically. 2s10s and 3m10y computed below the chart.

05

Major Bond ETFs

Price and context for TLT, IEF, SHY, LQD, HYG and AGG, alongside the government curve. The fastest read of the bond market.

06

Browser-Native

Opens in any modern browser, with one account working across up to five devices simultaneously. No install, no VPN, no IT ticket.

07

PDF Settlement Tickets

Every calculation exports to a clean PDF ticket with a unique reference number · for the back office, the audit trail, or your own records.

08

Priced for the Individual

One subscription, one account, five active sessions. $100 a year or $11.50 a month. No per-seat surcharges.

Subscription

One subscription.
Five devices, all at once.

One account, signed in on up to five devices simultaneously. No tiers, no per-seat surcharges. Cancel anytime.

The Account
Yield Calculator
$100/ year

Annual · $100. That works out to $8.33 per month, with the twelfth effectively free against monthly billing.

Save 28% vs monthly
Everything included
  • All five modules · Calculator, P&L, Portfolio, Curve, FX
  • Five simultaneous logins on a single account
  • Unlimited ISIN lookups and PDF settlement tickets
  • Portfolio with live marks, import/export
  • US Treasury curve with historical overlays
  • Bond ETF pricing · TLT, IEF, LQD, HYG, AGG and more
  • Email support, 24-hour reply
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