The assignment of the EUR funds to CHF carry traders is confirmed by the closer price of CHF-pegged pairs ( NZDCHF , AUDCHF , CADCHF and GBPCHF ) to EUR-pegged pairs ( EURNZD , EURAUD , EURCAD and EURGBP ) then to EURUSD . This is caused by the fact that JPY carry traders also carry the EUR and EUR-denominated debt securities.
The current closer price of CHF-pegged pairs ( NZDCHF , AUDCHF , CADCHF and GBPCHF ) to USD-pegged pairs (NZDUD, AUDUSD , CADUSD and GBPUSD ) will only to be seen during the USDCHF at 0.9900-1.0100 and their price volatilities will not close if and when the USDCHF far from 0.9900-1.0100. Thus, referencing their current price at current USDCHF 0.9900-1.0100 seems to be rationale but become irrational if and when the USDCHF far from the 0.9900-1.0100 in the future.
However, the EURCHF one-sided band policy is a policy maintained by the SNB to allow the EUR funds to be managed by CHF carry traders for carry trading by taking narrower risk of EURCHF target zone to off-set.