The proof is in the pudding. When I joined Vanguard in 1988, our average expense ratio was 0.46% and our flagship index fund—Vanguard 500 Index Fund—carried an expense ratio of 0.22%. Today those figures are 0.18% and 0.05% (for Admiral™ and ETF Shares), respectively as of year-end 2014.
Will you see lower Vanguard fund and ETF expense ratios in the future? If history is any guide, we expect so. It has happened nearly every year.
Note:
All investing is subject to risk, including the possible loss of the money you invest.