Dirty price vs clean price buy average

G-Secs trade with two prices:

Dirty price = Clean price + Accrued interest

Why this matters for buy average

Zerodha typically shows the clean price as your buy average (most common convention). Settlement happens at the dirty price.

So if you bought a 7% G-Sec at Rs 100 (clean), 3 months into the coupon cycle:

• Accrued interest: 7%/2 x (3/6) = 1.75% = Rs 1.75 per Rs 100 face value.
• Dirty price (paid): Rs 101.75.
• Clean price (buy avg shown): Rs 100.

The Rs 1.75 you paid is recovered at the next coupon.

When you sell

• Sale at clean price Rs 101 → quoted return is Rs 1 capital gain.
• But you also receive accrued interest at sale (since last coupon to sale date).
• Capital gain is computed on clean prices.

See also

• Money debited greater than allotment
• Government Securities (G-Secs) on Zerodha
• Calculate G-Sec returns
• Indicative yield on G-Secs
• Buy G-Sec on Zerodha
• Buy T-Bills on Zerodha
• Buy SDL on Zerodha
• SDL vs T-Bills vs G-Secs comparison
• Interest payment schedule for G-Secs
• Interest credit for G-Secs
• Maturity event for G-Secs
• Exit G-Sec before maturity
• G-Sec taxes on Zerodha
• G-Sec P&L on Console
• G-Sec nomenclature
• Allotment time for SDL/T-bills/G-secs
• G-Sec bid cut-off times
• Charges for G-Sec on Zerodha
• Edit / delete G-sec order on Kite
• Allotted G-Secs not visible
• T-bill allotment less than Rs 100 face value
• Reserve blocked basis for G-Sec
• CDSL SMS for T-bill maturity
• SDL/T-bill/G-Sec issuance calendar
• NRI G-Sec investment via Zerodha
• Zerodha bonds platform
• Bond YTM calculator
• Bond interest accrual on Zerodha
• Reserve Bank of India
• Zerodha

External references

• RBI G-Sec primer
• Zerodha

References

1. RBI, G-Sec pricing convention, rbi.org.in.
2. Zerodha, G-Sec buy average computation, support.zerodha.com.