NZX says more than 2000 lots have been traded on its dairy futures market.
The market, which allows buyers and sellers to lock in milk prices for delivery at a later date, got off to a slow start when it was launched last year.
NZX says it took nine months to reach 1000 lots traded, but the second 1000 lots took only eight weeks to register.
It says trading activity was particularly strong in July and August, especially in the whole milk powder market.
Derivatives manager Kathryn Jaggard says that while there's still a way to go to reach the super liquidity levels of globally traded commodities such as coffee and cocoa, it is a very strong start.