Contrary to stock funds, REIT funds are creatures of millions, instead of billions, of dollars. The fund market is dominated by Vanguard, whose Vanguard REIT ETF (which currently owns about 160 REITs) is the largest, with only about $62 billion in assets in recent weeks. The other three funds in the top four all recently have totaled less than $10 billion. Recently, all four have had significantly overlapping holdings and all — particularly Simon Property Group, which owns shopping malls — have concentrations in retail REITs. Investors seeking to avoid retail exposure have little choice but to seek active management. But this shouldn't be a deal breaker for passive-management aficionados.