TONAR

Tokyo Overnight Average Rate (TONA rate or TONAR) or Japanese Yen Uncollateralized Overnight Call Rate (Japanese: 無担保コールO/N物レート) is an unsecured interbank overnight interest rate and reference rate for Japanese yen.^[1][2][3] Mutan rate and TONA rate are the same things.

History

Japanese yen uncollateralized overnight call market started in July 1985.^[4]

Since December 28, 2016, the Bank of Japan has recommended the TONA rate as the preferred Japanese yen risk-free reference rate.^[5][6]

TONA rate is recommended as a replacement for Japanese yen LIBOR, which was phased out at the end of 2021, and Euroyen TIBOR, which will be terminated at the end of 2024.^[3][7][8][9]

Target rates

TONA rate

Bank of Japan target rates^[10]

Dates	Target rates
1998.09 - 1999.02	0.25%
1999.02 - 2000.08	Initially 0.15%, then 0%.
2000.08 - 2001.02	0.25%
2001.02 - 2001.03	0.15%
2001.03 - 2006.03	None (0%)
2006.03 - 2006.07	0.00%
2006.07 - 2007.02	0.25%
2007.02 - 2008.10	0.50%
2008.11 - 2008.12	0.30%
2008.12 - 2010.10	0.10%
2010.10 - 2013.04	0.00% - 0.10%
2013.04 - 2024.03	None (0%)
2024.03 -	0.00% - 0.10%[11]
2024.08 -	0.25%[12]

TONA Compounded Benchmarks

TONA Averages

TONA Averages are derived from the daily compounded TONA rate. The terms are 30day, 90days, and 180 days.^[13]

TONA Index

Assets when 100 was invested in TONA on June 14, 2017.^[13]