Comparing FOXBIT:BTCBRL with BITSTAMP:BTCUSD.
2017-09-01 BTCBRL=18190 USDBRL=3,1479 BTCUSD=4836 BTCBRL/USDBRL=5778 Spread=19%
2017-10-15 BTCBRL=17943 USDBRL=3,1626 BTCUSD=5556 BTCBRL/USDBRL=5673 Spread=2%
Probably the correction was necessary for BTCBRL but not for BTCUSD.