If you get $240 million in investments, and then sell the company for $250 million, I fail to see how it was successful (or "building a unicorn") at all.
The $200M investment was at a $1B valuation, thus it was an origami unicorn. However, one could argue that until someone actually forks over $1B, all valuations (even those of publicly listed companies) are on paper only.
Remember by the time you are taking $240M your valuation is either $750M or $1 billion (depending on the $250M being part of the valuation); all of which you have achieved with some $11M. That is a close to a 100x return. But even if you lost $750M/$500M in valuation before the deal and sold for $250M after raising $11M, that is still a 24x return.
