Jo Townsend, CEO of the Guardians of New Zealand Superannuation, which manages the country's $54.4 billion wealth fund, cautioned that U.S. equity returns are likely to slow. She noted that U.S. equities' returns over the past couple of years are close to double the annualized returns for the past 20 years, suggesting an eventual reversion to the mean. The fund returned 14.2% in the year to June 30.