Vanguard on Wednesday morning lowered the minimum initial investments for the low-cost Admiral Share classes of more than 50 active and passive funds. It dropped the ante for broad market index fund Admiral Shares to $10,000 from $100,000. Many of Vanguard's actively managed stock and bond funds also lowered their Admiral Shares minimums to $50,000 from $100,000.

The news means big savings for investors. For example, Admiral Shares of Vanguard Total Stock Market Index (NASDAQ:VTSAX - News) charge a rock-bottom fee of 0.07%, while Investor Shares with a minimum investment of $3,000 cost 0.18%. Fees for the Admiral Shares narrowly eke past Schwab Total Stock Market Index (NASDAQ:SWTSX - News), which last year lowered its expense ratio to 0.09% (after fee waivers) and has a minimum investment of $100. Meanwhile, Fidelity Spartan Total Market Index (NASDAQ:FSTMX - News) has a minimum investment of $10,000 and charges 0.10%.

The cost savings are similarly strong with Vanguard Total Bond Market Index VBTLX, where the Admiral Shares cost 0.12%, and the Investor Shares charge 0.22%. Another noteworthy difference is Vanguard Wellington Admiral Shares (NASDAQ:VWENX - News), which cost 0.23% compared with the 0.34% fee on Investor Shares.

While a $10,000 hurdle on index funds and $50,000 for active funds is steep for many investors, Vanguard says nearly half their individual investor client base should now qualify for the Admiral Shares. Investors rolling over assets from employer 401(k) plans may find the lower minimums more attractive.