Vanguard announced fee reductions for 168 mutual fund and exchange-traded share classes across 87 funds. The move will save investors roughly $350 million this year. The asset manager’s wide fee cut comes less than a month after Vanguard agreed to pay more than $100 million to the Securities and Exchange Commission over alleged violations involving its target date retirement funds.

Vanguard just announced its largest fee cut in the asset manager's history, which is great news for investors. Here's what you need to know.