0001469192 2012-12-17 2012-12-17 0001469192 ck0001469192:P0001-S000036714Member ck0001469192:S000036714Member 2012-12-17 2012-12-17 Other 2012-12-17 MAINSTAY FUNDS TRUST 0001469192 false 2012-12-17 2012-12-17 2012-05-25 MainStay Balanced Fund   <p class="MsoNormal" align="center" style="margin-top:0in;margin-right:0in;margin-left:0in;font-size:11.0pt;font-family:'calibri','sans-serif';margin-bottom:0in;margin-bottom:.0001pt; text-align:center;line-height:normal;text-autospace:none">  <p class="MsoNormal" align="center" style="margin-top:0in;margin-right:0in;margin-left:0in;font-size:11.0pt;font-family:'calibri','sans-serif';margin-bottom:0in;margin-bottom:.0001pt; text-align:center;line-height:normal;text-autospace:none">THE MAINSTAY GROUP OF FUNDS <p class="MsoNormal" align="center" style="margin-top:0in;margin-right:0in;margin-left:0in;font-size:11.0pt;font-family:'calibri','sans-serif';margin-bottom:0in;margin-bottom:.0001pt; text-align:center;line-height:normal;text-autospace:none">  <p class="MsoNormal" align="center" style="margin-top:0in;margin-right:0in;margin-left:0in;font-size:11.0pt;font-family:'calibri','sans-serif';margin-bottom:0in;margin-bottom:.0001pt; text-align:center;line-height:normal;text-autospace:none">MainStay Balanced Fund <p class="MsoNormal" align="center" style="margin-top:0in;margin-right:0in;margin-left:0in;font-size:11.0pt;font-family:'calibri','sans-serif';margin-bottom:0in;margin-bottom:.0001pt; text-align:center;line-height:normal;text-autospace:none">  <p class="MsoNormal" align="center" style="margin-top:0in;margin-right:0in;margin-left:0in;font-size:11.0pt;font-family:'calibri','sans-serif';margin-bottom:0in;margin-bottom:.0001pt; text-align:center;line-height:normal;text-autospace:none">Supplement dated December 17, 2012 (“Supplement”) to the <p class="MsoNormal" align="center" style="margin-top:0in;margin-right:0in;margin-left:0in;font-size:11.0pt;font-family:'calibri','sans-serif';margin-bottom:0in;margin-bottom:.0001pt; text-align:center;line-height:normal;text-autospace:none">Summary Prospectus and Prospectus, each dated May 25, 2012 <p class="MsoNormal" align="center" style="margin-top:0in;margin-right:0in;margin-left:0in;font-size:11.0pt;font-family:'calibri','sans-serif';margin-bottom:0in;margin-bottom:.0001pt; text-align:center;line-height:normal;text-autospace:none">  <p class="MsoNormal" style="margin-top:0in;margin-right:0in;margin-left:0in;font-size:11.0pt;font-family:'calibri','sans-serif';margin-bottom:0in;margin-bottom:.0001pt;text-align: justify;line-height:normal;text-autospace:none">  <p class="MsoNormal" style="margin-top:0in;margin-right:0in;margin-left:0in;font-size:11.0pt;font-family:'calibri','sans-serif';margin-bottom:0in;margin-bottom:.0001pt;text-align: justify;line-height:normal;text-autospace:none">This Supplement updates certain information contained in the Summary Prospectus and Prospectus for MainStay Balanced Fund (the “Fund”), a series of MainStay Funds Trust (“Trust”). You may obtain copies of the Fund’s Summary Prospectus, Prospectus and Statement of Additional Information free of charge, upon request, by calling toll-free 800-MAINSTAY (624-6782), or by writing to NYLIFE Distributors LLC, Attn: MainStay Marketing Department, 169 Lackawanna Avenue, Parsippany, New Jersey 07054. These documents are also available on the Fund’s website at mainstayinvestments.com. Please review this important information carefully. <p class="MsoNormal" style="margin-top:0in;margin-right:0in;margin-left:0in;font-size:11.0pt;font-family:'calibri','sans-serif';margin-bottom:0in;margin-bottom:.0001pt;text-align: justify;line-height:normal;text-autospace:none">  <p class="MsoNormal" style="margin-top:0in;margin-right:0in;margin-left:0in;font-size:11.0pt;font-family:'calibri','sans-serif';margin-bottom:0in;margin-bottom:.0001pt;text-align: justify;line-height:normal;text-autospace:none">At a meeting held on December 10-12, 2012, the Trust’s Board of Trustees, including the Independent Trustees, approved the following changes, effective February 28, 2013:   Principal Investment Strategy Change   <p class="MsoNormal" style="margin-top:0in;margin-right:0in;margin-left:0in;font-size:11.0pt;font-family:'calibri','sans-serif';margin-bottom:0in;margin-bottom:.0001pt;line-height: normal;text-autospace:none">The last paragraph of the Equity Investment Process section of the Summary Prospectus and Prospectus is changed to read as follows: <p class="MsoNormal" style="margin-top:0in;margin-right:0in;margin-left:0in;font-size:11.0pt;font-family:'calibri','sans-serif';margin-bottom:0in;margin-bottom:.0001pt;line-height: normal;text-autospace:none">  <p class="MsoNormal" style="margin-top:0in;margin-right:0in;margin-left:0in;font-size:11.0pt;font-family:'calibri','sans-serif';margin-bottom:0in;margin-bottom:.0001pt;line-height: normal;text-autospace:none">The Fund seeks to construct a broadly diversified portfolio across countries, sectors and industries using quantitative analysis to identify undervalued and overvalued securities. Investments are selected using an objective, disciplined and broadly-applied process, while seeking to limit exposure to risk.   <p class="MsoNormal" align="center" style="margin-top:0in;margin-right:0in;margin-left:0in;font-size:11.0pt;font-family:'calibri','sans-serif';margin-bottom:0in;margin-bottom:.0001pt; text-align:center;line-height:normal;text-autospace:none">  <p class="MsoNormal" align="center" style="margin-top:0in;margin-right:0in;margin-left:0in;font-size:11.0pt;font-family:'calibri','sans-serif';margin-bottom:0in;margin-bottom:.0001pt; text-align:center;line-height:normal;text-autospace:none">PLEASE RETAIN THIS SUPPLEMENT FOR YOUR FUTURE REFERENCE. <p class="MsoNormal" style="margin-top:0in;margin-right:0in;margin-left:0in;font-size:11.0pt;font-family:'calibri','sans-serif';margin-bottom:0in;margin-bottom:.0001pt;line-height: normal;text-autospace:none">