Microsoft 401k investment

All cash until next president in power, whoever he/she/it is.

100% s&p500 fund...will add some bonds in the coming years (just turned 24)

The S&P500 option is a great one (0.01% fees, if I remember correctly). Every other option is either mediocre or bad. I’ve always wondered if a) the Microsoft 401k team was given the option by Vanguard to get 1 great option and many bad ones, so they went with it (eg instead of only getting multiple mediocre options) or b) they don’t know what they’re doing

Read up on low cost index funds (bogleheads.org is a good resource) and especially the "3 fund portfolio". The default MSFT funds don't align with this but you can enable BrokerageLink for your 401k which unlocks way more choices. Fidelity has some low cost (or even no cost) index funds to chose from.