Stephen Blyth, the new CEO of the nonprofit Harvard Management Co. that manages Harvard’s endowment, recently voiced concerns over private equity valuations and future returns. In Harvard’s annual endowment letter, Blyth highlighted concerns of “potentially frothy markets,” noting the “environment is likely to result in lower future returns than in the recent past.”  The University’s hired hedge-funds are growing their cash positions in response and the endowment is becoming more discriminating in underwriting and return assumptions. Harvard wants to partner with managers astute at “both the long and short sides of the market.” For the past fiscal year, Harvard posted a 5.8% return, beating its internal benchmarks.