ETF of the Week: WisdomTree U.S. Efficient Core Fund (NTSX) ETF Trends CEO Tom Lydon discussed the WisdomTree U.S. Efficient Core Fund (NTSX) on this week’s “ETF of the Week” podcast with Chuck Jaffe on the MoneyLife Show. NTSX is an actively managed portfolio of US equities and US Treasury futures contracts. This fund is a strategy for those to rethink the 60/40 stock/bond investment methodology.The question is: does the 60/40 strategy still hold true in today’s market? No investment strategy is perfect, and 60/40 may be more of a default choice than true asset allocation. Despite its intention as a risk mitigator, the traditional 60/40 portfolio has been almost perfectly correlated to equity market returns throughout history because of its equity beta. This has been true across the U.S., developed international, and emerging markets.