Trades having figures after decimal point (=less than 1 Japanese Yen) in the trading amount does not allow "give-up" as the basic rule.

So, it is necessary to decide the figure length of trading price by considering not to have figures after decimal point (=less than 1 Japanese Yen) in the trading amount.

 

For the basic rule, please refer p6 of the following document.

Case : Nikkei 225 Option

Contract Specifications : http://www.jpx.co.jp/english/derivatives/products/domestic/225options/01.html

Tick Size : 1JPY, 5JPY, 10JPY (depend on option price)

Tick Size in J-NET : 0.0001JPY

Contract Unit :  × 1,000JPY

Trade Multiplier : 1,000

 

You can declare give up any normal trades because the tick size is more than 1JPY.

But the original tick size for J-NET is not suitable for give up because there is possible to have figures after decimal point (=less than 1 Japanese Yen), as 0.0001×1000=0.1.

 

You can declare give up if you place order with the tick size to 0.001JPY=1/1000, which is Reciprocal of Trade Multiplier.