In this empirical study, we analyze the relationship between carry trade positions and some key financial as well as macroeconomic variables using a multivariate threshold model. It is often stated that the Swiss franc serves as a funding currency. We therefore focus on carry trades based on the USD/CHF and EUR/CHF currency pairs over the period from 1995 to mid-2008. We conclude that carry trades are driven to a large extent by changes in investors' risk sentiment, movements in stock market prices and exchange rate fluctuations. The adjustments of carry trade positions to unexpected movements in these variables vary between periods of high and low interest-rate differentials (IRD). While a positive shock to the IRD is followed by a rise in carry trade positions during a period of low IRD, it will trigger a decline in these positions during a period of high IRD. These results suggest that the shock to the IRD itself is not enough to compensate investors for the increased foreign exchange risk. Moreover, a positive stock market price shock is associated with a rise in carry trade positions, since investors may use stock portfolios as collateral for liquidity. A sudden unwinding of carry trades leads to significant Swiss franc appreciation. Furthermore, carry trade activities 'Granger-cause' the nominal exchange rate in periods of low IRD. The Granger causality test results further indicate feedback trading.