US-listed ETFs achieved $2.2 billion in net inflows in May, according to analysis from investment data provider Morningstar. Once again, Vanguard recorded the largest ETF inflows, collecting $3.24 billion in net new assets in May and topping the chart for the second consecutive month. Vanguard’s focus on low-costs and core-holding funds has helped the index specialist add over $24 billion in ETF AUM so far this year.

Facebook’s stock market debut on Friday was more of a sputter than a splash. The company, which many thought would fly out of the blocks LinkedIn style, just about held its IPO price. Despite this, the social-networking giant’s reach is huge (over 900m users) and many investors are backing it to achieve great things. Facebook will eventually gain inclusion into a number of ETFs. We profile those, such as the Global X Social Media ETF (SOCL) and the First Trust Dow Jones Internet Index ETF (FDN), that are likely to hold it as a significant weight.

According to data from Morningstar, ETF asset flows took a breather in April, adding just $2.4 billion in new assets. Notably, all the net new flows went to taxable- and municipal-bond offerings. These two asset classes collected $5.1 billion while US and international equity ETFs shed $2.8 billion. Investment-grade and high-yield offerings took centre stage. Vanguard collected $4.4 billion in April, four times more than the next closest provider. The company’s ETF offerings last experienced a monthly outflow in February 2003.