[andruby]

Liquidity for the founders, early employees and previous investors can also be a reason to have another funding round.

[djhn]

What kind of situations would result in previous investors looking for liquidity? Assuming it is a trade for equity, it would be counter-intuitive do divest a fast-growing company if you are at least risk-neutral, which VCs should be?

[andruby]

Not VC's. But perhaps friends, family or fools who helped on a seed round. Granted, in the case of Github this seems very unlikely.