The effectiveness of Japanese interventions over the past decade depended in large part on the frequency and size of the transactions. Prior to June 1995, Japanese interventions only had value as a forecast that the previous day's yen appreciation or depreciation would moderate during the current day. After June 1995, Japanese purchases of dollars had value as a forecast that the yen would depreciate. Probit analysis confirms that large, infrequent interventions, which characterized the later period, had a higher likelihood of success than small, frequent interventions.