This paper analyses whether the Bank of Japan (BoJ) had fundamental concepts in mind when carrying out interventions in the foreign exchange market. We start by considering different long‐run fundamental target values based on a monetary exchange rate model and compare them with more ad hoc targets. Based on these findings, we explain the intervention probability for the BoJ after 1991 based on an ordered probit model by accounting for subperiods and asymmetric effects. It turns out that estimated fundamentally based values for the exchange rate provide additional information for the decision to intervene, in particular after 1995. However, short‐run ad hoc targets seem to be very important, in particular from 1991 until 1995, while medium‐run ad hoc targets gain importance at the end of the 1990s. Overall, we find a ‘leaning against the wind’ strategy in the event of overvaluation relies on ad hoc targets while intervention in cases of undervaluation seems to be guided more strongly by deviations from fundamental values.