https://meta.wikimedia.org/wiki/Wikimedia_Endowment
Hosting costs them $2.4M a year:
https://upload.wikimedia.org/wikipedia/foundation/1/1e/Wikim...
Less than ten years ago, one of their VPs said they could sustain their mission on "$10M+/year":
https://lists.wikimedia.org/pipermail/wikimedia-l/2013-March...
What he actually said in 2013 was this:
"WMF has operated in the past without staffing and with very minimal staffing, so clearly it's _possible_ to host a high traffic website on an absolute shoestring. But I would argue that an endowment, to actually be worthwhile, should aim for a significantly higher base level of minimal annual operating expenses, more in the order of magnitude of $10M+/year, to ensure not only bare survival, but actual sustainability of Wikimedia's mission. The "what's the level required for bare survival" question is, IMO, only of marginal interest, because it is much more desirable, and should be very much possible, to raise funds for sustaining our mission in perpetuity."
Total Wikimedia assets (Foundation + Endowment funds at Tides) stood at about $400 million in March 2022.