My DW usually contributes enough to her 403B at work to hit the maximum limit in November or December each year. With the market in steep decline, we decided to do what I did when I was retiring in July 2018, and increase her contribution to hit that maximum limit by July. We also maxed out her personal IRA with a buy order today (unfortunately, I maxed my own IRA about the same week as the peak of the market.) Anyway, we are really glad to be able to buy into this crazy decline. All these contributions will go into VTSAX (Vanguard Total US Stock Market).
I am not calling bottom, but I do feel very comfortable buying right now and over the next several months.