GRZ Bond Reopening Price Calculator
Description
GRZ Bond Reopening Price Calculator — Know What You'll Actually Pay
Since the Bank of Zambia's 31 March 2026 reform of the GRZ bond market, benchmark bonds (the 5, 7, 10 and 15-year tenors) are no longer auctioned as fresh issues every time. Instead, BoZ reopens the same bond line — same ISIN, same fixed coupon — again and again until it reaches a K10 billion outstanding target. Every reopening auctions a new cut-off yield, not a new coupon, which means the bond's price has to move above or below its K100 face value to reconcile the two. That leaves every investor asking the same question before they bid: what will actually leave my bank account?
This free GRZ bond reopening price calculator answers that question. Enter a benchmark bond's original coupon, issue date and maturity date from its first auction, plus a reopening's auction date and published cut-off yield, and it works out:
- Clean price — the bond's fair value at the new yield, per K100 nominal
- Accrued interest — the coupon days you owe the seller for buying mid-period
- Full (dirty) price — clean price plus accrued interest, the actual amount Bank of Zambia will debit for your face value
How this GRZ bond reopening price calculator works
A bond reopening keeps the original coupon fixed but auctions a new cut-off yield, so the calculator has to reconcile the two through price. If you're unsure how a fixed coupon and a moving yield interact, our guide to coupon rate vs yield for Zambian investors covers the underlying mechanics in plain terms. In short: when the cut-off yield falls below the original coupon, the reopening price rises above K100; when it rises above the coupon, the price falls below K100. This GRZ bond reopening price calculator automates that reconciliation using standard actual/actual day-count pricing, so you don't need to build the formulas yourself.
Built and checked against real GRZ bond auction data
The workbook includes a worked case study on the 10-year GRZ bond (ISIN ZM1000007642), tracking its price from its first auction on 13 February 2026 (16.60% coupon, allotted at par) through its reopenings in April, June and August 2026. The August 2026 auction (06/2026/BA) reopened at a 15.50% cut-off yield; the calculator's own actual/actual pricing model computes a dirty price of 105.72 per K100 — within a few cents of the Bank of Zambia's own published cut-off dirty price of 105.8171, a real-world check that the underlying bond math holds up.
A companion sheet, “Next 3 Auctions — Cash Forecast,” lets you plan ahead: enter your own yield assumptions for upcoming reopenings, including the confirmed 25 September 2026 auction (tender 07/2026/BA), and see an estimate of the cash you'd need on hand at settlement.
Who this GRZ bond calculator is for
Built for Zambian retail and institutional investors bidding into GRZ Treasury bond auctions who want to understand bond reopening pricing, accrued interest and settlement costs — not just the headline coupon or yield. Whether you're new to Zambia's government securities market or an experienced bondholder tracking BoZ's twice-quarterly benchmark bond auctions, this tool turns a published cut-off yield into the number that actually matters: what you'll pay.
Frequently asked questions
What does the GRZ bond reopening price calculator do?
It converts a benchmark bond's published cut-off yield into the clean price, accrued interest and full settlement (dirty) price you'll actually pay at a GRZ bond reopening auction, using the bond's original coupon, issue date and maturity date.
Why isn't a reopened bond priced at K100?
Because a reopening keeps the original coupon fixed and only the yield changes at auction. Whenever the new cut-off yield differs from the coupon, the price has to move away from K100 face value to keep the bond's return in line with the market.
How accurate is this GRZ bond reopening price calculator?
It's built on the standard actual/actual pricing convention and cross-checked against BoZ's own published results — in the 06/2026/BA case study, it lands within a few Ngwee of BoZ's official cut-off dirty price.
This tool is for planning purposes only and is not investment advice. Always confirm the current auction's published terms with the Bank of Zambia before bidding.
