The Globe and Mail reports in its Wednesday edition that the exchange-traded fund that pulled in the most money last month invests in the S&P 500 stock index. The Globe's Rob Carrick writes that the Canadian boycott of U.S. travel definitely has some traction, and commitment to buy Canadian in retail stores seems to be holding -- but investors in this country remain open to U.S. stocks, particularly in light of their sharp price decline in the past two months. A report from National Bank shows the top-performing ETF sector in April was international equity ETFs, which took in $3-billion in assets. U.S. equity funds had flows of $1.5-billion and Canadian equity funds took in $577-million. The ETF with the overall largest in-flows in April was the Vanguard S&P 500 Index ETF (VFV). It took in $665-million. The currency hedged version of this ETF (VSP) made the best-selling list as well with in-flows of $151-million, while the more diversified Vanguard U.S. Total Market Index ETF (VUN) took in $152-million. U.S. stocks have underperformed Canadian and international markets for the year-to-date. However, longer-term numbers favour U.S. stocks decisively, and U.S. stocks are essential for a diversified portfolio.