The State Bank of Vietnam’s central exchange rate was stable on 9 October at VND 25,130 per US$1, while the market-based mid-rate slipped slightly to 26,348 per US$1.
The black-market mid-rate, however, jumped to 26,880 per US$1, up 315 dong from the previous day, widening the gap between official and street rates.
The gap between the black-market and official exchange rates widened to VND 1,750 on 9 October, up from 1,432 a day earlier.
This lifted the premium on the street rate to 6.96 percent from 5.70 percent, the largest spread in some time.
Exchange rates, October 9, 2025
| 9 Oct | 8 Oct | Change | % | |
| SBV: Central Exchange Rate | 25,130 | 25,133 | -3 | -0.01% |
| Google Finance: Mid Market Rate | 26,348 | 26,361 | -13 | -0.05% |
| Black Market: Buy | 26,830 | 26,515 | 315 | 1.19% |
| Black Market: Sell | 26,930 | 26,615 | 315 | 1.18% |
| Black Market: Mid-market | 26,880 | 26,565 | 315 | 1.19% |
| Spread: SBV / Black Market MM | 1,750 | 1,432 | 318 | 22.21% |
| Spread: SBV / Black Market MM | 6.96% | 5.70% | 1.27% | 22.22% |
SBV short-term liquidity operations increased on 9 October, led by a sharp rise in seven-day repos to US$189.8 million from US$75.9 million.
Activity in longer tenors was mixed, with 28-day repos falling to US$189.8 million from US$265.5 million, while 14-day and 91-day operations both declined from previous levels.
Open market operations, October 9, 2025
| 9 Oct | 8 Oct | Change | % | |
| Repos – 7 Days US$ | $189,767,500 | $75,869,600 | – | – |
| Repos – 14 Days US$ | $39,720,615 | $75,869,600 | – | – |
| Repos – 28 Days US$ | $189,767,500 | $265,543,600 | – | – |
| Repos – 91 Days US$ | $37,929,969 | $75,869,600 | – | – |
Interbank interest rates rose across most short-term tenors on 9 October.
The overnight rate increased to 4.68 percent from 4.36 percent, while one-week and two-week rates also edged higher.
Longer tenors were mixed, with the one-month rate dropping sharply to 4.08 percent, and the six-month rate climbing to 6.40 percent.
Interbank interest rates, October 9, 2025
| 9 Oct | 8 Oct | Change | % | |
| Overnight | 4.68 | 4.36 | 0.32 | 7.34% |
| 1 Week | 4.74 | 4.56 | 0.18 | 3.95% |
| 2 Weeks | 4.86 | 4.65 | 0.21 | 4.52% |
| 1 Month | 4.08 | 4.99 | -0.91 | -18.24% |
| 3 Months | 5.13 | 5.26 | -0.13 | -2.47% |
| 6 Months | 6.40 | 6.20 | 0.20 | 3.23% |
See also: How Low Can the Vietnamese Dong Go? Why It’s Sliding & What Might Happen Next