About NihonRates
NihonRates is an independent publication covering the Japanese yen interbank market. We follow the two reference rates that anchor it, TIBOR and TONA, and write about what moves them. This page explains what those rates are, who produces them, and what we do with them.
What we publish
We are not a rate source. We do not publish TIBOR or TONA fixings, and nothing here can be used to look up a rate. JBA TIBOR is officially announced by the information providers JBATA has authorized - Refinitiv Japan, QUICK, Jiji Press, Bloomberg, and Nomura Research Institute. TONA is published by the Bank of Japan. If you need an authoritative figure for a contract, a valuation, or a filing, go to them.
What we publish is commentary and periodic Insights issues: how the term structure is shifting, where spreads are widening or compressing, and how stable fixings have been relative to their own history.
How we work
We read the daily figures published by the JBA TIBOR Administration and the Bank of Japan into a private database and compute our own statistics from them: changes in basis points, spreads between tenors and between series, rolling volatility, and where a period sits against its own history. Those statistics, and the commentary built on them, are what we publish.
What we do not publish is the underlying data. There are no rate tables, no downloadable series, and no API. This is a deliberate choice: our work is analysis of the market, not redistribution of anyone else's figures. Our methodology is described openly in each issue so that readers can judge the analysis on its merits, and the full derivation of every measurement type is set out in the Disclaimer.
TIBOR
The Tokyo Interbank Offered Rate is the Japanese yen term reference rate, administered by the JBA TIBOR Administration. It is published for each business day across a set of tenors from one week to twelve months, and it is calculated from rates submitted by a panel of reference banks rather than from a single transaction record.
Because it is a term rate, TIBOR carries both the expected path of overnight rates and a bank funding component. That second part is what makes the spread between TIBOR and compounded overnight TONA worth watching. More on TIBOR.
TIBOR Reference Banks
TIBOR is calculated based on daily submissions from the following 15 reference banks, representing diverse segments of the Japanese financial market. Each bank submits daily rates. The highest and lowest quotes are excluded, and TIBOR is calculated as the average of the remaining submissions.
Major Commercial Banks
Trust Banks
Specialized Financial Institutions
International Banks
TONA
The Tokyo Overnight Average Rate is Japan's overnight risk-free reference rate, published by the Bank of Japan from uncollateralized overnight call market transactions. Unlike TIBOR it is transaction-based and has a single overnight tenor, which makes it the natural benchmark against which term rates are read.
The Bank of Japan publishes a provisional fixing on the same business day and a final fixing on the following business day. Our published analysis uses final fixings only. More on TONA.
Where the figures come from
Everything we compute starts from these two publications:
- JBA TIBOR Administration - published daily at 4:30 PM JST
- Bank of Japan TONA market data - final results published on business days around 10:00 AM JST
NihonRates is not affiliated with, endorsed by, or acting on behalf of the JBA TIBOR Administration, the Japanese Bankers Association, the Bank of Japan, or any TIBOR reference bank, and it is not an authorized JBA TIBOR information provider.
Who runs this
NihonRates is operated by Arx Engineering. For inquiries and requests, including corrections and rights matters, contact us at www.arxeng.com/contact.