Your data vendor must use different codes to mine... which market/contract/delivery are you referring to, plus dates/times?
6J is not 6Y! FFS get it right! maybe FFS means Fat Finger Syndrome rather than anything else. Which seems somehow appropriate given Japanese Yen: http://www.chinadaily.com.cn/english/doc/2005-12/10/content_502260.htm http://www.bbc.com/news/business-29454265 Anyway, LA, yes the tick sizes have changed on Yen futures