MediumIV Macro Policy & Sovereign Debt28 September 2026, Monday · 13:00 TRT (UTC+3)
Benchmark bond's compound yield climbs to 40.46% as stocks slump
The simple yield on the benchmark bond maturing on 15 March 2028 rose from 36.68% to 37.03% on 28 September, and its compound yield from 40.04% to 40.46%. The simple yield moved above the 37% policy rate, and the BIST 100 fell 2.38% the same day.
According to an AA-sourced market summary, the benchmark bond's simple yield stood at 36.68% and its compound yield at 40.04% at the 25 September close. Capital's midday summary for 28 September showed the simple yield at 37.03% and the compound yield at 40.46% as of 13:00, a rise of roughly 35–42 basis points. The same day the BIST 100 fell 2.38% to 12,592.76 points, and the dollar traded at around 48.98 lira in the open market. The policy rate has been held at 37% since 10 September.
There is a trap in reading the data. Investing.com's Turkish 10-year series appears to have risen from 32.77% on 25 September to 35.67% on 28 September, and the 2-year series from 36.63% to 40.52%. These jumps of 290 and 389 basis points are inconsistent with the 35-basis-point rise in the AA benchmark data. The gap most likely stems from the series switching from simple to compound yield or to a new benchmark bond, so it could not be verified. Foreign demand is weak. CBRT data show non-residents sold a net 116.9 million dollars of government bonds in the week of 18 September. Their holdings fell from 18.15 billion to 17.43 billion dollars.
Talay assessment
Bottom line
The benchmark yield rising above the policy rate shows markets pricing a risk of CBRT tightening rather than easing. The move is far more limited than the 290–389 basis-point jumps on data sites; the real signal is its upward direction. If foreign selling of government bonds continues, near-term yield pressure will fall on domestic demand.
Likely effects
- Treasury financingNegativeWeeks
A higher benchmark yield raises the Treasury's cost of new borrowing during October, a month of heavy redemptions.
- Monetary policyUncertainWeeks
The simple yield exceeding 37% shows markets starting to price the possibility of a rate hike ahead of the 22 October MPC meeting.
- Data reliabilityUncertainWeeks
Series changes on data sites can lead to false readings of jumps; the benchmark bond and yield type should be checked every time.
Possibilities, ranked
- 1Stays above the policy rate55%
The simple yield fluctuates between 37% and 38%, and foreign selling continues on a limited scale.
Watch: Benchmark simple yield closing above 37%
- 2Sharp rise25%
With the fund investigation and oil pressure, the simple yield exceeds 38% and the compound yield approaches 41%.
Watch: Rising foreign selling of government bonds in the CBRT's weekly securities data
- 3Pullback20%
The risk premium eases and the benchmark simple yield falls back below the policy rate.
Watch: CDS falling below 240 basis points
Probabilities are calibrated judgement based on the sources, not measurement, and are revised as new information arrives. Not investment advice.
Market reaction
Indicators affected
- Benchmark simple yield▲ 37.03%
- Benchmark compound yield▲ 40.46%
- BIST 100, 28 September▼ −2.38%
Sources
- Capital — Markets at midday: latest on stocks, currencies and gold (28 September 2026)
- En Son Dakika (AA) — Markets at the close, 25 September 2026
- En Son Dakika (AA) — Markets at the close, 28 September 2026
- Investing.com — Turkey 10-Year Bond Yield historical data
- İş'te Mersin — Foreigners sold 558.4 million dollars of securities last week