You shouldn't expect a 150 mio investment in a startup to 8X in 10 years. At this kind of stage (C round), those returns don't exist anymore I think. The risk of it going to zero is also not that high. 
In the Farcaster case, it's probably shitcoinery where crypto VCs give 150 M and get tokens. The money probably won't even be spent. 

 Makes sense. So, less risk but smaller returns. Maybe 4x in 10 years? If it is much lower, it won't make much sense.