How to choose an interest rate data provider: 12 questions to ask

Last updated: 9 October 2026

Short answer: to choose an interest rate data provider, check five things in order: exact index and tenor coverage, where the quotes come from and how the curve is built, accuracy against your bank's mid (about 1bp once conventions align), reproducible curves for past valuation dates, and whether the licence covers your intended use.

This guide is built from the questions prospects actually ask us. Over the past year we have run dozens of evaluation calls with treasury teams, project finance modellers, valuation and audit firms, credit funds and fintechs building products on rate data. The same twelve questions come up again and again. Below, each one comes with why it matters and what a good answer looks like. We also say how BlueGamma answers it, so you can hold us to the same standard as anyone else.

The 12 questions at a glance

1. Do you cover our exact indices, tenors and currencies?

Check coverage index by index, not currency by currency. "We cover EUR" can mean 3M EURIBOR only, when your facility pays 6M. "We cover USD" can mean overnight SOFR, when your loan references a term rate.

Questions worth asking:

• Which tenors of each IBOR-style index do you have (1M, 3M, 6M, 12M)?
• Do you have the overnight index and its OIS curve as well as the term index?
• How far out does the curve go? Long-dated project finance and pension work needs 30 to 50 years.
• Do you have the adjacent data you will need next: fixings, FX forwards, inflation, government yields?

How BlueGamma answers it: forward curves and swap rates for 30+ currencies, plus fixings for the major overnight rates and benchmarks, covering both overnight (OIS) and term IBOR-style indices, with quoted tenors from 1 week out to 50 years. FX forwards, inflation and government yields sit on the same account. Every index is listed in the swap rate catalogue, so you can check yours before you book a call.

2. Where does the data come from, and how is the curve built?

Ask where the quotes originate and who builds the curve. The answer you want is that the quotes come from traded markets, that the provider can say which instrument sits at each point of the curve, and that the curve is bootstrapped with a documented method you can read.

This matters because a curve is only as defensible as its weakest link. If a provider cannot tell you which instruments sit at each point of the curve, or which interpolation it uses, you cannot explain a number to a credit committee or an auditor.

How BlueGamma answers it: curves are built from quotes on traded swaps, the same market the large terminals aggregate from. They are bootstrapped in-house using market-standard methods: par instruments to discount and forward curves on each currency's recognised conventions. The full process (observe, bootstrap, normalise, validate) is on our methodology page, and a curve-by-curve methodology document comes with every trial.

3. How close will you be to our bank's quote?

On mid rates, a good provider should be within about one basis point of your bank once conventions are aligned. Bigger gaps almost always come from when or how the number was built, not from a difference in the market.

When prospects compare us against their existing source, the gaps they find usually come from one of five causes:

The remaining spread between a provider's mid and the rate your bank quotes you is the bank's margin. That is why we show mid only. If you want to know what your bank is charging, you need an independent mid to compare against. Our guide to checking a bank's swap quote walks through it.

4. How often does the data update, and what does "end of day" mean?

Ask for the refresh rate and the exact snap time, and check that every data point carries a timestamp. "Live" and "end of day" mean different things on different systems, and a curve without a timestamp cannot be reconciled against anything.

Most modelling and valuation work does not need tick-by-tick data. It needs a recent quote during the day, and a close you can define for month-end and quarter-end.

How BlueGamma answers it: curves refresh every 30 seconds across the web app, Excel and the API, and every point is timestamped in UTC at source. For swaps and OIS, end of day is the last quote before that market stops updating: late afternoon London time for GBP and EUR (recently about 16:00 to 16:30 UTC), and into the evening for USD; daily history takes the last quote before midnight UTC. You can also pass your own valuation time and get the last quote at or before it, so you can set your own cut-off for each currency.

5. Can we pull a curve as of a past date, and how far back does history go?

You need point-in-time curves for any historical valuation date, and the history must not be rewritten. If the same date returns different numbers next year, a quarter-end valuation cannot be reproduced.

History depth varies by index, so ask for start dates index by index. Quant teams backtesting a strategy, or anyone who needs rates from before the LIBOR transition, should ask on the first call.

How BlueGamma answers it: point-in-time curves for any past valuation date in the app, Excel and API, and historical data is never rewritten. The longest series (6M EURIBOR, SONIA, Fed Funds, TONAR and BBSW among them) start in June 2018. €STR and 1M and 3M EURIBOR start in 2019, SOFR in March 2023, and more recently added indices later. The start date for every index is in the History since column of the swap rate catalogue.

6. How does the data reach our models?

The same number should reach every place your team works. Ask whether the API is as granular as the web app, whether you can request a past date through every channel, and whether there are download or call limits.

The usual channels are:

• Web app, for one-off downloads and checks
• Excel add-in, for financial models that refresh in place (how to pull a forward curve into Excel)
• REST API, for loan management systems, dashboards and products (interest rate API)
• MCP, so an AI assistant fetches real rates instead of guessing them

How BlueGamma answers it: all four channels serve the same curves, with no download limits. The MCP server works with any assistant that supports MCP, such as Claude or ChatGPT. Forward curves can be pulled at monthly, quarterly or semi-annual spacing, so they line up with your model's payment dates.

7. Can it price and value our actual trades?

Raw curves are only half the job for most teams. Ask whether the provider can price the trade you will actually do and value the swaps you already hold.

For project finance and real estate, that means amortising swaps and blended rates across construction and operations. For borrowers it often means caps, including forward-starting ones. For treasury and audit it means a mark-to-market for every existing swap at every reporting date.

How BlueGamma answers it: the swap pricer takes your amortisation schedule and returns the mid swap rate for that exact profile. The MtM calculator values existing swaps on any date, with PV01 and a downloadable report. Caps and swaptions have their own pricers (cap calculator). If you want to check the maths, we show a mark-to-market calculation with a worked example.

8. What can we do with the data under the licence?

Licences usually separate internal use from showing data to anyone outside your organisation. Describe your real use case before you sign and check that the licence terms cover it. This is the question most often left until too late.

The uses that tend to need checking:

• Putting curves or rates in client reports or valuation reports
• Displaying data on a website, in a client portal or behind a member login
• Building derived data, such as your own curves, spreads or indices, on top of the provider's data
• Redistributing data inside a product your customers pay for
• Sharing outputs across group entities

How BlueGamma answers it: every plan covers using the data inside your organisation, including pricing and valuing your own trades, checking bank quotes and forecasting interest costs in your models. Showing customers results calculated from our data, or the underlying rates and curves themselves, needs a wider licence agreed with our team up front; the pricing page sets out both. Tell us your use case on a call and we will talk it through. If you are building a product on rate data, see rates feed for your product.

9. How is pricing structured, and does it fit how much we use?

Ask what you are paying for: seats, currencies, API calls, or a flat fee. Then ask what happens when your usage changes. A pricing model that suits a trading desk rarely suits a team that needs two currencies and a monthly refresh.

Questions worth asking:

• Is pricing per user, per currency, per call or flat?
• Is there a smaller plan if we only need one or two indices?
• Are there daily or monthly download limits?
• Are the API and Excel included, or are they extra?
• Can we pay monthly, or is it annual only?

How BlueGamma answers it: plans run from Individual to Enterprise, priced per seat, with no download limits. Every plan's price unlocks in the app when you start the trial, and our pricing page shows what each plan includes.

10. Can our auditors trace and reproduce a valuation?

An auditor will want to know where a valuation came from, and may ask six months later. You need a methodology they can cite and inputs you can reproduce exactly for the valuation date.

How BlueGamma answers it: the methodology document covers construction curve by curve, and rating agencies already rely on the same data in their published work. We can reproduce the chain for any past valuation: the market inputs as at that date and the curve built from them. Swaps and OIS are timestamped to the second, FX and government debt to the business day. See independent swap valuation for audit and quarter-end valuations.

11. What does the trial include, and how should we test it?

A trial should give you the real data and enough time to run it through your own workflow. Agree what success looks like before it starts. Trials without agreed criteria tend to drift, and the decision stalls.

How BlueGamma answers it: a 14-day free trial with no card needed. We can also help you compare BlueGamma against your current source at the same timestamp and work through any remaining difference.

"Please compare our curves to what you already get. Maybe for one week you just pull the curves, compare. Make sure the conventions are right. And then we have a very clear case of: can we proceed or not."

A one-week validation plan

1. Pick three indices and one valuation time where you already hold numbers from your current source or a bank.
2. Align the conventions first: fixed-leg frequency, day count, calendars and discount curve (see question 3).
3. Compare par swap rates at 2, 5, 10 and 30 years. On mid, expect about 1bp.
4. Price one real trade, such as an amortising swap from your model or an existing swap from a bank valuation statement.
5. Pull a past quarter-end curve twice, a few days apart. The numbers should be identical.
6. Run it in your workflow: refresh the Excel model, or make the API call your system will make.
7. Confirm the licence covers your use case.

12. What don't you cover?

Every provider has gaps, and a good one tells you on the first call. The question saves you a trial on something that will never fit.

What BlueGamma does not do: news, equities, chat or trade execution. We do not cover power or commodity forwards, mortgage-backed securities or intraday government bond prices. We do not advise, broker or trade. We focus on getting the number right. If you need one of those, a broader terminal or a specialist vendor is the better fit, and we will say so.

BlueGamma at a glance

Try it against your current source

The fastest way to answer most of these questions is to run the validation plan on your own numbers. Start a free 14-day trial, or book a call and we will run the side-by-side comparison with you.

Frequently Asked Questions

What does an interest rate data provider do?

An interest rate data provider supplies the market rates and curves that finance teams use to model debt, price hedges and value derivatives: swap rates, forward and discount curves, fixings and often FX forwards. A good one also documents how each curve is built, so the numbers can be defended to a credit committee or an auditor.

How close should an interest rate data provider be to bank quotes?

On mid rates, a good provider should be within about one basis point of your bank's mid once conventions are aligned. Larger gaps usually come from snap time, fixed-leg frequency, interpolation or the choice of discount curve, not from the market data. The spread between an independent mid and the rate a bank quotes you is the bank's spread and margin.

Where should an interest rate data provider's data come from?

From traded markets, with a curve built by a documented method you can read. Ask which instrument sits at each point of the curve and which interpolation is used, so you can explain a number to a credit committee or an auditor. BlueGamma builds its curves in-house from traded-market quotes, as set out on our methodology page.

Does BlueGamma have an API and an Excel add-in?

Yes. The same curves are available in the web app, the Excel add-in, the REST API and an MCP server for AI assistants, with no download limits. Past valuation dates are available through every channel.

Can I use interest rate data in client reports?

It depends on the licence. Most licences separate internal use from showing data to people outside your organisation, such as clients, portal users or customers of your product. Describe the use case before you sign and check that the licence terms cover it.

How should we test an interest rate data provider during a trial?

Run a short validation plan on your own numbers: align conventions, compare par swap rates against your current source at the same timestamp, price one real trade and pull a past quarter-end curve twice to check it does not change. One week is usually enough. BlueGamma offers a 14-day free trial with no card needed.

Can I connect interest rate data to ChatGPT or Claude?

Yes, if the assistant supports MCP (Model Context Protocol). Connect the BlueGamma MCP server and the assistant fetches live swap rates, forward curves and FX forwards when it answers, instead of relying on numbers from its training data.