What is the purpose of Mega Bucks?

There is a currency exchange in the Mission Control menu. You can exchange either Earth currency or Moon currency for Mega Bucks. What is the point of this?

You can now use Mega Bucks to purchase Mega Tickets. 1 Mega Ticket will permanently boost the profit of one investment by 777%.

Mega Tickets cost 10 Mega Bucks, but you can buy 10 Mega Tickets for 90 Mega Bucks (which is equivalent to buying 9 and getting 1 free).

In the release notes (as of the last update, when it was implemented):

Convert your Earth and Moon Dollars into Mega-bucks. What does it do? That’s a secret! (Coming Soon)

So it isn't released yet, but it should have a purpose in one of the forthcoming updates.

There is currently no use for Mega Bucks. From the name "Currency Exchange", it sounds like in the future you should be able to exchange Earth and Moon currency through Mega Bucks.