This study focuses on the behavior of open-ended mutual fund investors when encountered withmultiple information signals of mutual fund?s historical performance. The behavior of investors canbe reflected on their decision to subscribe or redeem their funds from mutual funds. Moreover, we observethe presence of ambiguity within investors due to multiple information signals, and their reactiontowards it. We apply a Fama-McBeth Regression technique for equity mutual funds, fixed incomemutual funds, and balanced mutual funds that are effective during the period of February 2010 untilFebruary 2015. Our finding shows that open-ended mutual fund investors do not only have sensitivitytowards past performance information signals, but also have additional sensitivity towards theambiguity of multiple information signals. Because of the presence of ambiguity, investors considermore on negative information signals and the worst information signal in their investment decisions.