Hello LTR, I have a sep-Ira and I am taking an rmd for several years.I would like to keep 25% in the prime money market to cover my rmd in case of a long market down turn or side way movement. I've got 25% in vwiax and 25% in vwenx. I would like 25% in another fund. I love vwiax and vwenx, so what fund should the 4th 25% be into. Thank you.
Unfortunately you did not mention your preference for the safety of those last 25%. If your portfolio is already big enough to sustain you through a long comfortable retirement even in an adverse market, then I would keep the last 25% in something reasonably safe and conservative, such as either short- or intermediate-term investment grade corporate bonds (VFSUX or VFIDX respectively).
If you your portfolio is not particularly large or if you are also investing for your heirs or charity and wish to take more longer-term risk in stocks, then foreign equities available via VTIAX would provide good potential for higher returns (with higher risk, of course) and be a great diversifier to US-heavy Wellington and Wellesley that you hold now.
If you go the VTIAX route for the last 25% then your overall portfolio will be 25% money market, 25% corporate bonds (via Wellington and Wellesley), 25% US large-cap value equities (again, via Wellington and Wellesley), and 25% international equities, for the net result of 50% in stocks and 50% in cash/bonds with reasonably good diversification. Such a 50/50 portfolio would generally be my recommendation for upper limit of risk for somebody in retirement. I think that level of risk is justified today since today's stocks have much better potential for keeping up and beating inflation than today's bonds, though unfortunately both are on the pricey side overall.
But again, if you already have more than enough money, then I would go with something more conservative than VTIAX.