Looking at two funds, FBIOX and IBB, it seems that they mostly invest in the same things (at least the top 10 holdings are roughly similar), but the expense ratio for FBIOX is .81% vs. .48% for IBB.
Why is this? Is this something about the biotech sector, or because mutual funds incur more capital gains, or just a difference in strategy? (Maybe FBIOX is more actively managed vs. IBB, which just tracks an index)